Ah, I think I see now, I misunderstood how the cap worked. Max-hp hits are capped at 10%.
Okay, so if a head had 3M hp, and say Gnut hits it, the damage is capped at 300k
but now if a head is decapped, it has 6M hp, so that same hit would do 600k, but also gets the decap 200% multiplier, so would hit for 1.8m ?
no, the 10% limit is a hard cap. regardless of any other multipliers or modifiers, a max hp hit cannot exceed 600k (or whatever 10% of the boss in question's hp is). it is a limit per hit though, so in gnut's case he would deal 1.8 million combined over the course of his attack.