10.8k-ish base hp, phantom gun = 30% and Diabolos unleashed = 20%, giving you 10.8k * (1 +30% +20%) = 16.2k-ish.
What I want to know is how he can get all the debuffs to stick on Och so consistently... Is Perseus' VoF that strong? Might change my order for unlocking T4 souls if it is, though that batch of T4 souls is like a year away for us anyway.