Originally Posted by
Calore
You want Blighted Souls and Corrupt Weapon because they are another source of damage which can Critic, and thus trigger Void of Madness buffs.
Not for the damage they directly do, which is quite low.
So yes, 1 points in those feats is best option generally.
You should also want Vile Gluttony for same reason, and use a rotation which keeps Zone of Gluttony up all the time.
Fresh lvl 80 with no VoM can skip all these feats until he gets it.
With VoM, they are really reccomended for every build.