I've been looking all day now and still can't find an answer! Simple Q. Does Malph's Brutal Strike buff damage on base damage or base+buffed damage? Working on a team nearly centered around the rocky bowling ball so I need some info.

I believe it's total damage, I may be wrong.

pretty positive its not just base dmg, at near end game with brutal strikes, i crit over 1k

I dont think this can be achieved if its just base dmg

One of the reasons he can be built as a DPS. Phantom dancer and Infinity edge will give you more than 600 crit when W is activated.