Lemme run through an idea first, before I get to work.

The Corruption is going to be 'Pack Leader' or whatever, essentially the ability to control lesser (read: stupid) Grimm and have some mental influence over anything else. A mind control/telepathy power, essentially, to act as communications for team wombo combos and damage control for when other Shade-of-Black members go into a bipolar rampage.

Thoughts?