I like the concept of tricking enemies into defeating themselves as well. I think killing things should still be possible, but unrewarding. So if all you do is mindlessly attack, you end up falling behind the curve and being doomed to failure. Similar to how summoners worked pre-0.28 in DCSS: more powerful than usual, but more unrewarding, resulting in eventually falling behind and being doomed.
Killing things should either come at some kind of cost ({creature}'s mind cries out into the void, spreading the disease among hundreds more!) or just not get you anywhere ("That felt strangely unrewarding.")
Another thing to mention is that I LOVE gameplay referencing lore. For example, some kind of antisynergy with the Unhinged and Saintly. Or with the Ordered and Feral.