I enjoyed getting the "1 armor for each kill" perk, which was the first one that felt like a really big change especially with an armor based attack.
Then it felt kind of unfair as I got 4x as many enemies as weapons for 3 consecutive floors, depleting my weapon stash and the shops and rewards in between not offering anything that would do or enable damage (like a two mana point potion when i need 5 for a single attack). The spell was of limited use as it is most effective when i got many enemies turned around, but that ofc also depletes my armor (and eventually i have no other options if my weapons depleted despite never leaving a weapon on the table and buying more often enough).