well, if i was in the 170-180 range for malenia, i suppose it's because i did play a lot of co-op on that character. either way, the higher the level the more diminished the return, especially if you're like me where i'm not playing numbers or using buffs well (i was using a poison/rot build, which i feel is less conducive to damage buffs, i was aiming for recurrent damage, not really the damage spikes). it's an achievement whether it took 35 hits or 50 to down her.
but speaking of numbers i've tried doing a build that actually focuses on the numbers, going for a frenzied flame (and black flame for some of the more fire-resistant bosses) and I've come across an absolutely miserable bug. Current patch (1.09) has a bug where many damage boost buffs simply do not work on incantations/spells, or sometimes breaks the spells completely. I had spent a little bit of time gathering jellyfish shield, fire grant me strength, faith talisman, etc. So I get behind the putrid avatar that drops the fire damage buff tear, load up all my buffs and sneak behind, charge up flame of frenzy, and then drown the avatar in yellow plasma, only for the health bar to be completely unaffected. I could downgrade to a previous version, but i think i'll just wait for a fix, even though it's been a few months now. Just a heads up for anyone trying something similar.