Note: Unmarked spoilers for the plot. There's no other way to make a comprehensive guide to this subject.

Welcome to this guide to the Morality Gauge in Dawn of War II: Chaos Rising. This will give you a comprehensive guide not just to the Corruption & Redemption mechanics other guides give, but also to each squad's abilities at either end of the scale.

Everyone except Davian Thule has a Morality gauge that indicates what kind of guy they are. Every time you do something heinous, use tainted wargear or suchlike, you and any squads who deployed with you gain Corruption points and become burdened with the weight of their actions. By contrast, behaving honourably and using sanctified wargear allows you to gain Redemption points, easing your conscience and your troubled mind.

There are seven levels on the Morality scale that indicate what level of Corruption (if any) you have or if you are pure after all. Those levels are as follows:


While Pure, you get a single trait or ability which you immediately lose if you gain 4 or more Corruption points, be that over time or in one sitting. Likewise you gain 6 Corruption traits at 4, 8, 12, 16, 20 and 24 points, and also likewise you'll lose them if you redeem yourself past the point of qualification. No two Space Marines have the same abilities, whether Purity OR Corruption, so you have lots of options open to you about how you want to play. Like I said before, Davian Thule is the exception.

By the way, once you hit the bottom of that gauge, you're stuck there. The gauge will simply be frozen at 24 with no way to redeem yourself. So you'd better be sure you want to end up there if you intend to tamper with the tools of Chaos often.

Here I will explain each corruptible Marine's ability tree and what each means. Note that despite what I said before there is some overlap - just not very much, or in a cookie-cutter manner.

A major part of the story is that one of your squads has betrayed his fellow Blood Ravens to the Black Legion invaders before even the events of the game. Who the traitor is is not decided by random chance; his identity is tied to your squads' Morality gauges. If one of your squads has at least 4 Corruption points, he's a viable candidate to be revealed as the traitor towards the end of the game. If there's more than one, the squad with the most Corruption points is the traitor. If multiple squads have the same Corruption rating, the one with the lowest Will is the traitor. If you manage to make it to the end with no corrupted squads, Techmarine Martellus becomes the traitor instead.

When the traitor is revealed, he abandons you and retreats to a Black Legion base on planet Aurelia. Your second-to-last mission is to track him down and execute him for his treachery. Each fight plays out differently, and the keen-eyed among you will recognise some of the abilities your former comrade-in-arms can unlock through his non-corruption skill trees. After you beat him, the traitor drops a legendary item that your squads can then use or donate to the librarium to receive another legendary item from. I'll go over these items in the next section.

Bear in mind that these are always dropped, irregardless of whatever other wargear you have, so don't expect randomised loot tables or anything.

• One of the perks for Tarkus of total Corruption is that he gets a bolter and set of armour that only he can use to their full potential. As you donate the Blighted Bolter and the Blighted Power Armour to the Librarium, they come back more powerful and more demanding in Corruption each time until they become legendary items. As the traitor, he drops an alternate version of the Blighted Bolter that anyone with bolter privileges can use. If you donate it, you get the Holy Bolter of Purification, a Purity bolter that has 100% accuracy and boosts ranged damage by 75%.
  
• Avitus drops a suit of corrupt Terminator armour given to him by Chapter Master Kyras, called Lost Honour of the Blood Ravens. No one can use it because it's Avitus-exclusive. Simply donate it to receive the Honour of the Blood Ravens, which is identical except the FC, Tarkus and Thaddeus can now use it. It provides a few neat bonuses.
  
• Cyrus drops a sniper rife that no one can use because no one else can use Cyrus weapons. Donating it earns you Lessons of the Veteran, an awesome accessory that grants +5 to all attributes.
  
• Thaddeus drops The Pact of Thaddeus, an accessory which represents a copy of his bargain with Ulkair. It's a corruption item with no other bonuses than +4 Corruption, which means nothing this late in the game, and can be redeemed for The Caution of Thaddeus, a Redemption item that improves your armour rating and energy, although if you're badly corrupted by the final battle, you're in too deep to turn back now.
  
• Jonah drops the Snare of Jonah Orion, a force staff which allowed a Daemon of Chaos to erode his psychic defenses and ultimately possess him. Since you have no Librarian and can't use it any more, go right ahead and donate it. It'll give you the Deathmask of Jonah Orion, which projects an anti-daemon aura around the user. Not a bad item given that the final boss is a daemon and the penultimate boss spams Bloodletter spawns.
  
• Martellus drops his Chaos-made Iron Warriors servo-arm, Gift of the Iron Traitor. No one can use it so just donate it to receive the Blade of Steel, a neat power sword that has a 10% chance to instantly destroy enemy vehicles.

The way I see it, there are basically three paths you can take with regards to Morality: the Path of Full Purity, the Path of the Designated Traitor and the Path of Full Corruption. Allow me to outline them and what they mean here:

Simple enough. You play to preserve the purity of every single squad under your command. That means you avoid all Corruption opportunities, bring the relevant squads on personal missions (Thaddeus to Spire Legis, Cyrus to rescue his initiates, Tarkus vs. the Eldar, Jonah on the second Judgment of Carrion mission and Avitus vs. Araghast the Pillager) and so on. The best part of this is that you don't lose anyone, but it also means having to fight Martellus. And no offense to Martellus, but his boss fight is one of the hardest in the entire campaign, only the last two being any harder. Holy crap. This will earn you Martellus' anti-vehicle sword of doom, and allow you to have all your squads to choose from for the final battle.

This is where you pick out a squad you want to be the traitor and arrange for his corruption ahead of time. I suggest building a functional party of 4 squads that doesn't include the squad you chose; that way, his absence will go unmissed. This path is useful for purity playthroughs that you don't want to face Martellus during, or for neutral playthroughs. To ensure the squad you chose is the traitor, make sure he has at least 4 Corruption points by the end of the second Calderis mission. I recommend leaving him behind during his personal mission for an easy 5 Corruption points, without the need for juggling corruption and redemption items or doing anything bad during your campaign.

The opposite of Full Purty, obviously. Do all Corruption side-missions, indulge your Corruption powers constantly and don't seek Redemption - in fact, don't do any redeeming sidequests unless you get plenty of Corruption points in the same mission to counteract it. One strange move I used last time is to go backwards to go forwards: certain Redemption missions give you powerful and highly corrupting Corruption items like the Aegis of Obliteration (+4 Corruption Terminator armour) and the Book of Lorgar (a +3 Corruption accessory for Jonah). This oxymoron is one you should definitely exploit.

The ending of the campaign is dependent on the Morality of your squads, and I see only the two pure endings and the fully corrupt ending as being worthwhile. That's why I recommended these paths. If you want to aim for other endings I'm sure there are guides for those as well.