Warhammer 40,000: Regicide tells the story of the Blood Angels through a dialogue at the beginning of each mission. Don't worry, there is full voice dialgoue. An interesting way to tell a story in a turn-based strategy game. Although I would have loved cutscenes, I like this approach as well.

I also made this guide for myself so that I can easily put each piece of dialogue in one place and read it all like a whole.

In the game starting video: A guy, probably an Imperial Guard but not confirmed, is trapped in a Bunker and says that he keeps hearing voices and has detected an unusual movement, but there is no life there.

In the campaign starting video: The Orks attacked the planet Hethgar Prime and killed the Imperial Garrison there, in response a Chapter of the Blood Angels was sent to deal with the Orks, during the landing, the Space Marine Captain was cut off from the rest of the forces and now a young Blood Angel, Captain Dracomedes, has taken command of his troops.

Mission 1: The Forest Clearing
Librarian Baldessar: The Orks may have lured us here, Commander. The astropathic relay that has sent the initial distress signal is still functional. It is located at Bunker 383, in the ice wastes to the north.
Captain Dracomedes: It is difficult to imagine such a subtle strategy from the orks. Their brutality is matched only by their impatience for a good fight.

Mission 2: An Alien Mind
Librarian Baldessar: Hmm....
Captain Dracomedes: What is it Baldessar? Do your psychic gifts reveal something?
Librarian Baldessar: I sense a disturbance deep in the forest. A powerful alien mind, perhaps an enemy psyker.
Captain Dracomedes: Tactical Squad Theron, move out and secure the astropahtic relay. If the orks truly baited us here, let us learn why. Baldessar, you will accompany me and the rest of our forces. I want to find this "disturbance" of your and put an end to it, permanently.
Tactical Sergeant Theron: The enemy is pressing the attack!
Captain Dracomedes: They will regret standing in our way, Space Marines, attack!

So far a classical Warhammer 40.000 story, it reminds me of Dawn of War and Space Marine. A chapter goes to a planet to find orks there, but as always there is more than meets the eyes. It has become a Warhammer 40.000 template story at this point. I would love to see much more interesting scenarios, but then again, this type of scenario works and people never seem to grow tierd of it.

Mission 3: Return Fire
Librarian Baldessar: Commander Draco, I sense no survivors. The colonists have been whiped out, and the orks infest this world like a disease.
Captain Dracomedes: If that is true, Baldessar, then we are the cure.
Devastator Sergeant Nemos: They cannot stand against us!
Captain Dracomedes: Wipe them out!

Mission 4: Blood of our Enemies
Librarian Baldessar: These orks are cunning commander. We should consider a cautious approach.
Captain Dracomedes: I have a hunger for battle than can only be slaked with the blood of our enemies. Let us take to the field, and give the orks what they want, a fight that they will never forget!

Mission 5: Seizing Ground
Captain Dracomedes: Hethgar Prime belongs to the Imperium. It is time we remind these alines of that fact!
Assault Sergeant Lycaon: Assault Squad, deploy!
Captain Dracomedes: Strike from the skies, brothers!

Mission 6: Make Haste
Tactical Sergeant Theron: Commander, our Scouts have secured Bunker 383 and the astropahtic realy.
Captain Dracomedes: Well done, brother Theron.
Tactical Sergeant Theron: Report ork forces on the move in this region.
Librarian Baldessar: The psykic disturbance is growing stronger, more focused. It is jamming our signals.
Captain Dracomedes: Throne curse these orks!
Librarian Baldessar: We must complete our mission quickly so that we may reinforce Theron and his squad.
Captain Dracomedes: Agreed. Blood Angels! Advance!

Until mission 6 those have been filler missions, meaning few story-related elements and more gameplay. I don't mind that, in fact I like that. Even in movies where you have no gameplay, some people don't like filler episodes, but I feel that filler episodes or missions in this case helps you understand the lore and the ordinary life of the world you're immersed in better.

Mission 7: In a Flash
Zuggtoof da Weirdboy: I can feel the WAAAGH in me' head! ZZAP!
Captain Dracomedes: That ork, did he just teleport away?
Librarian Baldessar: Yes, commander, and worse than that. That is a ork weirdboy. They posses strong, if undisciplined, psychic powers. It is likely he is the source of the disturbance I sensed earlier.
Captain Dracomedes: In that case, he must be nearby. Forward!

Mission 8: Drive then Back
Librarian Baldessar: Commander, it is possible that the weirdboy's presence is another trap.
Captain Dracomedes: This Warboss Gobklaw must be a cunning one indeed.
Librarian Baldessar: First, luring us here with a distress signal and then using the weirdboy as a distraction.
Captain Dracomedes: Orks rarely think so far ahead, what is he planning?
Tactical Sergeant Theron: Under heavy attack by ork forces.
Captain Dracomedes: Brother-Sergeant! We're losing your signal!
Tactical Sergeant Theron: Being overrun, cannot hold, position.
Librarian Baldessar: We must deal with the weirdboy and the orks in the forest quickly, commander. The Warboss must have sent other forces against Bunker 383 and Sergeant Theron.
Captain Dracomedes: Let us have a reckoning with the greenskins!

Mission 9: Subjucation
Zuggtoof da Weirdboy: I have the power or Orkiness!
Captain Dracomedes: Throne! The weirdboy's teleporting again!
Librarian Baldessar: He is a dangerous foe. If we can corner him, I may be able to use my powers and stop him from escaping.

Mission 10: Suffer not the Unclean
Rozenkrump da Shoota Boy: Not as many Boyz around...
Gobstern da Shoota Boy: Let's come back another day.
Zuggtoof da Weirdboy: Just make sure my head is aiming the right way!
Librarian Baldessar: Commander Draco, I have focused all my will on the weirdboy. It requires all my concentration, but I have ensured he cannot teleport away from us.
Captain Dracomedes: This time, we have him! There is no escape for you now, alien!
Zuggtoof da Weirdboy: Uh oh... I can feel my power fading.

I like this story so far. Although a generic Warhammer 40.000 story I love the idea of a cunning ork that is able to plan ahead and managed to spit the Space Marine forces and now the main force is forced to chase the Weirdboy to secure their passage to help Tactical Sergeant Theron at Bunker 383.

Mission 11: No Respite
Librarian Baldessar: The weirdboy is dead, but the orks have ambushed the forces sent to secure the astropathic relay.
Captain Dracomedes: We must move quickly to help Sergeant Theron and the Scouts. Forward, Brothers!

Mission 12: Take it Back
Captain Dracomedes: Strange. Our signals are no longer being jammed, but there is no response from Sergeant Theron or his squad.
Librarian Baldessar: Let us hope we are not too late.
Captain Dracomedes: The orks defend the entrance. If I know Theron, he is holding out within.

Mission 13: The Eternal March
Librarian Baldessar: You had led us well, commander.
Captain Dracomedes: We must launch another attack against the bunker without delay. Theron and his squad are still in danger.
Librarian Baldessar: We are Space Marines, we live to slay the enemies of the Emperor.

Mission 14: Beset on all Sides
Librarian Baldessar: Our victory is assured, commander.
Captain Dracomedes: The orks thought they could keep the astropathic relay out of our hands. They were wrong.

Mission 15: The Blood of Angels
Librarian Baldessar: The astropathic relay is our, commander.
Captain Dracomedes: This is the source of the signal that brought us to Hethgar Prime to begin with.
Librarian Baldessar: Commander, I sense no survivors.
Captain Dracomedes: What? No... Theron, the scouts. The orks, these foul aliens have slain our brothers and desecrated their bodies. Hear me, greenskins! I will cleanse this world of your kind! This, I swear.

The anger issues of Captain Dracomedes are probably a hint that he will eventually get the Black Rage. For those that don't know the lore of Warhammer 40.000, the Blood Angels have a genetic defect that if they go way too angry they eventually lose their mind in that anger and become mindless killing machines. The death of Sergeant Theron's squad may be the beginning of that rage.

Mission 16: Salvage
Brother Tameus: Commander Draco.
Captain Dracomedes: Report, sergeant.
Brother Tameus: We salvaged a locator beacon from the bunker. With this, we can summon reinforcements from our ship in the orbit.
Captain Dracomedes: Excellent. Adding the terminators to our ranks will ensure we can wipe out the orks infesting this world.

Mission 17: Slay them All
Librarian Baldessar: Hmm...
Captain Dracomedes: What is it, Librarian?
Librarian Baldessar: I am not certrain yet, commander. But I sense something strange.
Brother Cirio: The enemy is pressing the attack!
Captain Dracomedes: Slay them all!

Mission 18: Gripped by Fury
Brother Tameus: Commander, the orks are bringing more forces to bear against the bunker.
Captain Dracomedes: Hmm... perhaps they seek to keep us pinned down here, but why?
Librarian Baldessar: Commander, some of our brothers are gripped by fury. Their thirst for blood is becoming too strong.
Captain Dracomedes: The Red Thirst.
Librarian Baldessar: It is our Chapter's curse. Some never recover and become berserk warriors of the Death Company. We must be watchful before they succumb to the Black Rage.

Here we go, I had expected Captain Dracomedes not his troops, but being the Blood Angels the Black Rage had to be mentioned. And it seems the Warboss Gobklaw's plan is not over yet.

Mission 19: Paid in Blood
Captain Dracomedes: Our brothers paid with their lives for this bunker. We will not allow the orks to take it from us!
Terminator Sergeant Orpheus: Terminators hold the line!

There is a cutscene presenting Warboss Gobklaw before this mission.

Mission 20: Gobklaw
Librarian Baldessar: Commander, I sense a powerful force approaching. I believe it is the alien's leader.
Captain Dracomedes: The warboss?
Librarian Baldessar: He is a powerful opponent, and his presence inspires other orks to fight even more fiercely.
Warboss Gobklaw: Right, humies. This planet belongs to the orks!
Captain Dracomedes: Never, alien! We are blood angels, and we will end you.
Warboss Gobklaw: Waaagh!

Mission 21: We Must Push On
Captain Dracomedes: We must push to Hethgar Prime's capital city. The orks are using the city's ruins as their encampment.
Brother Tameus: We will drive them out, Captain Draco.
Captain Dracomedes: In the name of the Emperor, we shall.

Mission 22: Visions of the Past
Librarian Baldessar: Commander, our brothers...
Captain Dracomedes: They have not recovered from their fury?
Librarian Baldessar: No. Our battle-brothers have caught the Black Rage. They only see visions of the past, and our slain Primarch.
Captain Dracomedes: We must gather these warriors into the Death Company.
Librarian Baldessar: They are consumed with destroying the enemy. Any enemy.
Brother Tameus: More orks sighted!

Mission 23: A Strongpoint
Captain Dracomedes: Hejopolis. Once, this city was the center of this world. The Orks have defiled it.
Brother Tameus: Captain Draco, what are your orders?
Captain Dracomedes: Blood Angels! For our brothers, for our chapter, destroy the orks!

Mission 24: Hejopolis
Librarian Baldessar: The ruins of Hejopolis provide the orks with many hiding places.
Captain Dracomedes: Agreed, our counsel, Librarian?
Librarian Baldessar: Let us establish a strongpoint, and the send forth the Death Company.
Captain Dracomedes: Wish that I could go with them, and make these streets run red with ork blood.
Librarian Baldessar: Dracomedes...
Captain Dracomedes: Fear not, Baldessar. My duty is clear. I must command, although this decision is one that I wish I did not have to face.

Mission 25: A City to Cleanse
Captain Dracomedes: Though you have been consumed by the Black Rage, you are still strong. Though vision of our Primarch's death cloud your mind, you are still resolute. Though insanity takes you from our ranks, you are still Blood Angels.
Librarian Baldessar: I shall accompany the Death Company, and do my best to guide them.
Captain Dracomedes: Go with honor, Brothers!

Mission 26: The Death Company
Librarian Baldessar: Normally, only a Chaplain can harness the Death Company's berserk bloodlust. Perhaps my psychic powers will serve to give them a direction for their fury. Come, my afflicted brothers. We have a city to cleanse.

Halfway through the story and we finally get to play with the Death Company. Which plays exactly the same as a regular Blood Angels company except that their color is black with some red crosses. The story is nice so far, the Blood Angels received a distress signal of Hethgar Prime, they sent a squad to Bunker 383 where the signal came from, that squad was under attack and by the time the main army reached it the squad was dead. This infuriated Captain Dracomedes and we can see glimpses of that even now, then in the constant ork attacks led Captain Dracomedes to believe that the orks are pinning them down for some reason, Warboss Gobklaw personally attacked them, they defeated his army but did not kill him. Then headed for the capital city of Hejopolis, where they secured a stronghold and then sent the Death Company in the city.

Mission 27: Fury Unleashed
Librarian Baldessar: The orks cannot stand against the unleashed fury of the Death Company. I believe it was wise to separate them from the rest of our forces. Captain Draco is skilled, but I fear the Chapter's curse may affect even him.

Mission 28: Moments of a Shattered Past
Librarian Baldessar: The Death Company sees every enemy through a distorted lens. For them, they re-live the Primarch's final battles, experiencing the mythic moments of a shattered past. All Blood Angels honor the Death Company, for their fate may one day be our own.

Mission 29: A Reckoning
Librarian Baldessar: The orcs hold the bridge, it could well be another trap. The Death Company and I will clear the way. And after that, we will have our reckoning with Warboss Gobklaw.

Mission 30: Angelfall
Librarian Baldessar: Commander Draco, I have carried out your orders. The ork encampment is just ahead.
Captain Dracomedes: At last!
Librarian Baldessar: The warboss is a cunning foe, we should be careful.
Captain Dracomedes: Gobklaw, face my wrath!
Librarian Baldessar: Commander! Wait!
Warboss Gobklaw: Hurr hurr hurr! You know how to fight, I'll give you that. Come on and have a go, if you think you've had enough.
Librarian Baldessar: Commander Draco...
Warboss Gobklaw: That humie hit hard, alright. But I'm still the strongest.

The Death Company's moment, in spite of its epic entrance, was pretty boring. Only Librarian Baldessar had a monologue, which is understandable, since the Death Company is probably too angry and already lost to their fury to talk, but they could have worked something around this to make that event more interesting.

Mission 31: Disturbance
Librarian Baldessar: I have assumed command. Captain Draco has been returned to our strike cruiser, the Deus Vitae. There, he has been interred within a sarcophagus in an attempt to heal him and cleanse the fury from his blood. I am sensing unusual warp disturbances across the planet. Are the orks attempting another distraction? I have dispatched terminators to investigate one such site in the forests.

Mission 32: In the Deep
Terminator Sergeant Orpheus: We have reached the deep forests, librarian.
Librarian Baldessar: Excellent, and the warp disturbance?
Terminator Sergeant Orpheus: It is difficult for us to track down. The signature is like one I have never seen before. Alien, but not of the orks.
Librarian Baldessar: Keep searching. For the commander's sake, let me know if you discover anything more.

Mission 33: Disruption
Librarian Baldessar: Curious, I sense another warp disturbance in the city. There may be more ork weirdboys, or perhaps something else.
Terminator Sergeant Orpheus: Your orders?
Librarian Baldessar: Find the source, and wipe out the orks nearby. Whatever these disturbances are, they are more dangerous in the hands of the greenskins.

For the record, mission 33 was an insanely fun mission, but completing it the secondary objective was hard. You had 3 terminator rooks and the enemy had 5 stormboy knights, there were a lot of obstacles, now that I hear the story and look around in the mission I can realise I'm in a forest, which makes the setting of this battle interesting.

Mission 34: Focus
Terminator Sergeant Orpheus: Warp disturbance pinpointed.
Librarian Baldessar: Excellent. The warboss has placed many of his ork forces around these points. Make him regret that choice.

Mission 35: Behind the Throne
Librarian Baldessar: The warp disturbances are liked to bunker 383 as well. All this time, another alien force has been around the scenes.
Terminator Sergeant Orpheus: Another ork force closes in on the bunker, Librarian. We will wipe them out.

Mission 36: Our True Enemy
Librarian Baldessar: I believe I know something of our true enemy now. First, however, we must deal with the greenskins and their warboss.
Terminator Sergeant Orpheus: The orks have regrouped in the ruins of Hejopolis.
Librarian Baldessar: Then that is where we must go. Forward, Blood Angels!

Mission 37: Convergence
Brother Xanthus: Report from the Deus Vitae, Brother Librarian. All ork forces on Hethgar are converging on the city.
Librarian Baldessar: We must be getting closer.

I like the way they made the change from act 2 to act 3 with the introduction of the warp disturbances and the possibility that the orks are not the real enemy hear. It only adds more mistery on top of Warboss Gobklaw's cunning. The ending of act 2 was a bit anti-climatic, with Captain Dracomedes giving in to the Black Rage and being defeated but not being killed by Warboss Gobklaw, but it was understandable as they need to keep him alive for his return, whether as part of the Death Company or recovered from it.

Mission 38: Den of Witches
Brother Xanthus: Ork psykers detected!
Librarian Baldessar: More weirdboys! Caution, brothers. These orks are dangerous.

Mission 39: From the Shadows
Weirdboy: Oh, my head!
Librarian Baldessar: I sense another mind directing yours, greenskin. Who pulls your strings from the shadows?
Weirdboy: My poor head is going to burst!

Mission 40: Cleanse and Purge
Librarian Baldessar: This city is going to be your tomb, alien!
Weirdboy: So much WAAAAGH! energy! We must be doing good. I see sparks! I gotta use my powers quick! Hahaha! Zap! Zap! Zap!
Librarian Baldessar: No more tricks, greenskin. Blood Angels! Cleanse and Purge.

I believe that the plot of act 1, act 2 and act 3 were equal in size, but to make more missions they spread the act 2 and 3 on 20 levels while act 1 had only 10 levels. As a ressult, the act 1 had a lot more going on in each level while so far act 2 and act 3 have shown less information with each level. Let's hope the last 10 missions of the campaign will change that and the ending will be good.

Mission 41: Enemies of the Imperium
A Disembodied Voice: Kill. Kill! It is what you were made for.
Dracomedes the Fallen: Agggh!
A Disembodied Voice: Wake and kill!
Dracomedes the Fallen: Alien witch. You are in my mind.
A Disembodied Voice: Kill your enemy, Space Marine. And do not stop until you have had your fill of bloodlust.
Dracomedes the Lost: Kill, the enemy.
Librarian Baldessar: Brother Librarian, urgent report from Deus Vitae.
Brother Xanthus: Is it the Captain?
Librarian Baldessar: Captain Draco has awoken from the sarcophagus.
Brother Xanthus: I sense something is very wrong.
Librarian Baldessar: The captain took a drop pod on the planet's surface. And the Death Company is with him.
Brother Xanthus: Our true for has shown themselves at last. The captain is being influenced by an alien psyker. We must find him, quickly.
A Disembodied Voice: Sweep the forest clear of your enemies, Space Marine.
Dracomedes the Lost: Orks. Enemies of the Imperium.
A Disembodied Voice: Yes, Space Marine. Slay your enemies. Let your bloodlust grow.

What an amazing start, I was just complaining about a lack of content in each mission, and here it is. Although I would have liked it Librarian Baldessar wouldn't have figured out so quickly that Captain Dracomedes is possesed, but would have genuinely believed he has succumbed to the Black Rage.

Mission 42: No Matter the Odds
A Disembodied Voice: The orks have servered their purpose. I have no further use for them.
Dracomedes the Lost: Destroy, the greenskins. For the Emperor!
A Disembodied Voice: No, my Space Marine. Destroy them for me.

Mission 43: You Have No Choice
A Disembodied Voice: The more you shed blood, the deeper you fall beneath my power.
Dracomedes the Lost: No, must, ressist!
A Disembodied Voice: Kill for me, Space Marine. You have no choice.

Mission 44: First, the Orks
A Disembodied Voice: Your conditioning is strong, Space Marine. Even a mind as strong as my own has difficulty controlling you.
Dracomedes the Lost: You, will not win here, alien!
A Disembodied Voice: First, the orks. Then, we will deal with your fellow "Blood Angels".

Mission 45: A Fitting End
A Disembodied Voice: The ruins of a human city, fitting that it should end here. Go, my Space Marine. Make the streets run red with blood.
Dracomedes the Lost: Aaaghh!

Mission 46: As I Command
Librarian Baldessar: Captain Draco. He is here. And being influenced by an alien mind.
Brother Xanthus: What do we do, brother librarian? To fight fellow Blood Angels, is unthinkable.
Librarian Baldessar: We need only to get close to him. Then, I will focus my powers to break the alien's hold on Draco's mind.
A Disembodied Voice: Now! Strike the Blood Angels down!
Dracomedes the Lost: No, I cannot!
A Disembodied Voice: You will do as I command, Space Marine.
Librarian Baldessar: We will see about that, alien. Captain Draco! Hold on, battle-brother!

Looks like the twist got a re-twist.

Mission 47: Suspicion
Captain Dracomedes: My mind is free. And my bloodlust subsides. Thanks to you, Baldessar. I am in your debt for removing the witch's grasp.
Librarian Baldessar: It is good to have you back, Commander.
Captain Dracomedes: We must not waste time. Can you track the alien witch?
Librarian Baldessar: I can. The warp disturbances here, and elsewhere on Hethgar Prime, point out to the cathedral in the capital city.
Captain Dracomedes: Then that is where we must go to end this.
Librarian Baldessar: The warboss will be waiting for us.
Captain Dracomedes: I am counting on that. The cathedral. Warboss Gobklaw chose his citadel well.
Librarian Baldessar: I begin to suspect that much of the ork's cunning was directed by another.
Captain Dracomedes: We will find out for sure soon.
Librarian Baldessar: The time is now, commander. The Warboss approaches with his strongest troops.

Mission 48: Focused Wrath
Librarian Baldessar: It is good to fight at your side once more, commander Draco.
Captain Dracomedes: This planet has left new scars. And thought new lessons. Even to me.
Librarian Baldessar: Your fighting skils have never been sharper.
Captain Dracomedes: And my wrath is focused. Let us show these orks our resolve!

Mission 49: Fire and Blood
Captain Dracomedes: The warboss sends his finests against us.
Librarian Baldessar: His bodyguards, I believe.
Captain Dracomedes: I've had enough of these greenskins. Hethgar Prime requires cleansing. We will purge it with fire and blood.

Mission 50: This Ends Now!
Librarian Baldessar: At last. The warboss reveals himself.
Brother Xanthus: The greenskins will desecrate this place no more.
Captain Dracomedes: Gobklaw, this ends now!
Warboss Gobklaw: I'll have your head on my bosspole, you git!
Librarian Baldessar: We are the angels of death!
Brother Xanthus: We are the scions of the Primarch, Sanguinius.
Captain Dracomedes: We are the sons of the Angel.
Warboss Gobklaw: Come on then! Orks is made for fighting. And winning!
Captain Dracomedes: For the Emperor and Sanguinius! Death to the alien!

Ending:
Librarian Baldessar: Commander, now that the warboss is dead, I can sense clearly the presence of another force.
Captain Dracomedes: The alien witch who clouded my mind?
Librarian Baldessar: The same. She was the one who lured the orks here in the first place and nearly caused us to destroy each other.
Captain Dracomedes: These tactics of deceit and trickery. They are the mark of the Eldar.
Librarian Baldessar: Correct. Commander, I believe our fight for this Sector has just begun.
Captain Dracomedes: If that is so, then the Blood Angels stand ready.

I was expecting a great twist and the act 3 delivered. The story overall was interesting, unfortunately, we won't know what happened next. There was supposed to be an update or DLC that includes the Eldar, since they were the ones controlling Captain Dracomedes, but it never came out. The fact that it has 50 missions reminds me of Elastro Mania, that game also had 50 missions, game with these many missions are rare nowdays. But this is not the whole story, there is also a ork side of the story.

There is another part of the story where you play with the orks under Warboss Gobklaw. I don't know whether it's a prequel, explaining how Gobklaw came to power or happening at the same time as the Space Marine story, as it cannot be a sequel since he was killed. But I didn't include that story here, I have not yet finished it.