There's so many things scuffed about this, to the recording resolution to the deaths, but really the icing on the cake is not realizing that the achievement is for the story Ultimate boss and not Proud.
I didn't think it'd be as funny to do another recording though because honestly I wouldn't have the same reaction again.
So yeah, try as I might I couldn't beat the final damage check with capped out jump slam and had to resort to Glass Cannon.