In Warhammer 40k: Dawn of War II I have been collecting blighted armour and weapons with negative armour ratings but various other stats perks. I am unable to donate these items for XP (unlike most other items), so is there any hidden bonuses from collecting it? i.e. will these items combine to make some kind of super armour if I collect the whole set?
These weapons are removing corruption from the squad wearing it, in Chaos Rising. You have negative stats, to prove that you are worth, and pure to the eyes of the Emperor.
However, if I remember good, such items are appearing also in Dawn of War 2, without the expansion. The "purification" bonus is not shown then, you will see it only if you finish the campaign and use this save in Chaos Rising.