I’m not noticing extra loot, have 4x diabolic creatures in my party.
The ability description is kind of misleading - you won’t necessarily find “extra” loot, but instead you’ll just find “better” loot. I’ll clarify the description in the next update. With that said, it’s not going to be very noticeable on the first few levels of the dungeon but you’ll notice it a lot more as you travel deeper.
Edit: I’m also going to buff the effect a little bit for the next update since it’s slightly lacking at the moment.