So since SE boosted the sh*t out of this, I'd thought I'd share some of my findings with you guys.
So far, Despoil has yet to take effect on a NM.
The debuffs seem to vary by mob family, or job. For instance, despoiling a bird in Abyssea - Misereaux will always yield slow or acc down (Slow being the most common it seems), never matt down, which is good.
Bones in ulegaund range (The mages) always yielded magic defense down, but probably has something else.
Demons in Ulegaund range always yielded attack or defense down, no exceptions, mage jobs and melee jobs alike. The attack down would also trigger after Amano's attack down, and vice versa.
This is beginning to look like a very predictable pattern, which I like.
I'll be doing more testing once I hit 85, but feel free to share your debuffs paired with mob area, job and type in this thread.
Edited, Sep 9th 2010 8:05pm by ElvaanTHF