This guide is to give a quick and concise walkthrough for most of the NPC's questline for others to use during their own playthroughs! I discovered after my first playthrough, that there were a number of NPC questlines I missed, solely because I missed some very early checks, locking me out of a good portion of content in the game, including a couple of secret bosses!

The following information does contain some spoilers relating to locations, bosses and story beats.

If any of the information I'm putting here is incorrect, there are questions about the quest lines, or more details are required, input is always accepted, as I'm not one to generally write guides.

Note: I am missing the Reservoir of Pain's questline as I have not personally completed it.

1. Meet Nameless Nhero and Lady Sco at the degenerated abyss area in The Depths, talk to the two of them and agree to assist them in fighting the corrupted Toad abomination, and kill it. (This must be done early in the game, I am uncertain of the specific timeframe, but I believe it must be done prior to beating The Grinder during your first visit to The Depths.)

2. Meet Nhero within Festivity Row, he will be found prior to the Lift leading up to the top level of the tower, and will mention being attacked by an assailant (Vengeance), and feels down on himself. Give him the Remembered Shield of Inspiration (Shield is dropped from the Heroic Statue boss, and remembered at the Heart of Nostalgaia), he will cheer up and you may continue onward.

3.Nhero will pop up at the Gnom the Consumer boss fight, have him assist you and continue on your way.

4. Nhero will appear much later at the The Keep of the Stolen Crown, talking with Blade the Bold halfway through the stairway puzzle, talk with the two of them and just continue as you would.

5. Nhero will appear once more during The First Sequence, in an area featuring two corrupted toad abominations (Up a ladder into a hole in the sky, prior to the 'Training' section), he will ask you for assistance to slay the two. Accept his help, kill the monsters and speak to him once more.

6. Nhero shows up at the Beacon above the Heart of Nostalgaia, talk with him.

7. Nhero shows up one last time as a hostile mob in the final area of the game, blocking your path and carrying a nice new shield in hand. Kill him, receive his withered icon, his new shield, the Shield of Inspiration, and his Nameless Sword. Congratulations, you've completed Nhero's tragic quest!

1. Meet Lady Sco and Nhero within The Depths, speak with them and agree to assist them with killing a corrupted abomination. Afterwards, talk to them again. (This must be done early in the game, prior to beating The Grinder boss fight and leaving The Depths.)

2. Meet Lady Sco again within Festivity Row, she is now on one of the open outdoor terraces, wielding a nice new greatsword, with her old Scope Cutter lying on the floor beside her. Talk with her a bit, take her old sword if you want, and move on with your journey!

3. Lady Sco next appears in the Warlock Wilds, standing in front of a hollow log that leads to the Lost One village and the Crone Maiden's hut. Talk with her, hear more of her philosophy and head on out.

4. You'll next find Lady Sco behind bars in the Rehabilitation pit, in a cell right before you enter the Keep of the Stolen Crown. She asks for your assistance to find some way to appear civilized. Bring her the remembered Civilization armor set, and she'll gratefully accept it and thank you for your help! (The Civilization Armor is found within the stairway puzzle section of the keep, and must be remembered in the purification room in the first floating chapel nearing the top of the keep.)

5. Lady Sco will appear before the Keep of the Stolen Crown's Great One fight and offers her assistance, accept her aid and win the fight! Afterwards you can talk to her briefly before you leave the boss room.

6. From the Oreshaft Smeltery before The Depths, you must cross the flattened bridge nearby with your Turn Flat ability (Learned from the Old Man to reach NPC City) to reach a snow-covered plateau across the way. (The Location where the Edge of Entropy is remembered) Lady Sco will meet you there as a hostile mob, seeking to unburden you. Kill Lady Sco and receive the Civilization armor, her Withered Icon and her Unburdened Greatsword!

Congratulations, you've completed Lady Sco's questline!

1. Complete the first step of Lady Sco/Nhero's quest lines, otherwise you cannot move past the second step of Blade the Bold's quest line.

2. Meet Blade the Bold at the end of the Quest Reward Vault, he is in a cell to the left, and talks about his missing icon and how he is a terrible hero. You will eventually find his Withered Icon in a shortcut between the start of Warlocks Wilds and the Oreshaft Smeltery, bring it back to him and he'll be appreciative of your help.

3.Blade appears in the Keep of the Stolen Crown alongside Nhero, discussing the merits/responsibilities of being a hero. He is within the Stairway puzzle area, talk with the two of them and head on through.

4. Blade appears one last time prior to The Narrator's Boss Fight, accept his assistance for the boss fight and win! You will find his armor and his Withered Icon in the empty room after the Boss Fight is finished.

With this, you should have completed Blade the Bold's bittersweet questline!

1. Complete Nhero and Lady Sco's first step of their questline, otherwise Vengeance's first step will not trigger.

2. At the top of the Lift leading to the top of the tower in Festivity Row, you'll spot Vengeance dash past a door up a set of stairs. Follow her up the stairs to an open terrace and initiate her miniature boss fight. Beat her, and she smoke bombs away!

3. Vengeance will appear once again after the Gnom the Consumer boss fight, she'll ask you to follow then lay down her weapon. Talk to her, hear what she has to say and then continue your journey.

4. At the entrance to the moat surrounding the Keep of the Stolen Crown, Vengeance will be present, talk to her again, move on.

5. After slaying The Great One at the Keep of the Stolen Crown, you'll meet Vengeance at the base of the keep, talking to the Old Man. Talk to the two of them, and receive the Heirloom weapon from Vengeance.

6. Remember Heirloom within a side room featuring a two-dimensional castle within The First Sequence. You will find Vengeance moping around the altar right above the Heart of Nostalgaia, give her the Heirloom and watch her be inspired.

6.5. Vengeance will ask you a question whether or not you would to take the throne after defeating all the Great Ones. If you answer 'Yes', she will appear as a hostile mob in the Bedroom right before the Final Great One's boss room. If you say 'No', she will appear as shown in step 7.

7. Right before the Final Great One boss fight, Vengeance asks to assist you to seek her vengeance on the Great One. Accept her assistance, beat the boss and enjoy the fact that you've completed her questline!

This is the most complex of the questlines in the game and features two additional boss fights and a new ending for achieving it!

1. You must receive the Maiden Crone's Gourd from the Maiden Crone in the Warlocks' wilds. The Maiden Crone can be reached through Hollow Log Tunnels leading from the Lost One Village after you've received the map from killing the hostile 'Fairy' mob in the Servant Sword's remembering location. When you reach the foggy area through the downward paths in the Hollow logs, you'll follow the blue sparkles/wisps leading you through the fog.

After traversing the fog, you'll be greeted by an old hut, a grave with a familiar pig-boss half-buried in it and a tombstone you can knock over for a shortcut. Talk to the door of the hut to speak to the Maiden Crone and get the gourd.

Give the Gourd to The Innocent found in the empty house in Oreshaft Village, and watch as he vanishes!

Return to the Maiden Crone's hut, listen to the funny antics and receive your reward, a Rune!

2. Collect the Stern Glare from NPC City and Remember it.

To remember this item, you must first collect the Chrysalis Tooth in Festivity Row (Near some bushes prior to the Theater) and remember it at the abandoned stall on the side of the road in Warlocks' Wilds.

Then you must collect the Edge of Entropy (Near Gnom's Statue in Oreshaft Village) and remember it in the secret shrine on the snow-covered plateau across the flat bridge from the Oreshaft Smeltery.

Once you have remembered the Edge of Entropy, collect the Stern Glare from the side of a trash can on a side path next to the entrance to the First Sequence. You can remember it at the Heart of Nostalgaia.

3. Complete the story until you are on the way to fight the Final Great One. You will meet the Innocent outside of the Hall of Heroes and talk to him. Talk to the Maiden Crone as well, and then return to the Spirit of Heroism Statue in the Hall of Heroes.

Challenge the Spirit of Heroism and defeat it in a new boss fight, receiving the Essence of Heroism!
Talk to the Maiden Crone once again, and bring the Essence over to the Old Man next to the Heart of Nostalgaia. Give the Old Man the Essence, and then proceed to interact with the Heart and sacrifice the Essence of Heroism to it afterwards.

Talk with everyone one more time and head on to finish your journey.

4. After you've defeated the Final Great One and return to the Heart of Nostalgaia, you'll be greeted by the Maiden Crone who tells you to meet with the Old Man and the Innocent at the heart.

Talk to the Old Man, he asks for the Stern Glare, give it to him. Talk to the innocent, then talk to the Old Man again and tell him you're ready.

Watch the Cutscene, and congratulation, you've finished the Innocent's questline!

From here on out, you can get the Innocent's help, interact with the Heart of Nostalgaia and initiate with the secret Final Boss of the game!

With this, you should now have all the information you need to successfully complete all the questlines in the game, barring The Reservoir of Pain's questline!

Hopefully this guide was of use to someone out there, as I know I personally had to scrounge the corners of the internet to find this information in snippets from one location or the other.