Issue 1244 (http://www.adom.de/forums/project.php?issueid=1244) states that Orb Guardian corpses were buffed. Recently this buff (constant +stat boosts from them) seems to be reverted, and they are useless again (and maybe even more, given amount of corruption).
I think that this was done accidentally, and this corpses should be reverted to their previous behavior.
Adjusted again. The whole attribute increase balancing topic really is a major annoyance. You patch something in one corner and it "breaks" in another.
Perhaps in this case it would be useful to have a discussion where all the attribute altering things are talked about? There you'd have all cases and opinions about them in one place to make a final decision and implement all at once instead of a case to case basis depending on what's being actually bug reported...
I've eaten, that is to say I've had PCs that have eaten, Nuurgy and the measley 1 point of mana they've received on each occasion isn't really worth the 4 or so corruptions received in addition.