I'm having a bit of trouble wrapping my head around the specific wording in the Blood Fury Tattoo's initial charge burning ability.
When you hit a creature with a weapon attack, you can expend a charge to deal an extra 4d6 necrotic damage to the target, and you regain a number of hit points equal to the necrotic damage dealt.
The only hang-up I have is if I were to have an additional effect, such as Hex, that would add necrotic damage to the attack before the charge's additional effect is used.
You place a curse on a creature that you can see within range. Until the spell ends, you deal an extra 1d6 necrotic damage to the target whenever you hit it with an attack. Also, choose one ability when you cast the spell. The target has disadvantage on ability checks made with the chosen ability.
The way I see it, there's two interpretations, either you gain HP based solely on the extra 4d6 added by the charge, which I think is the knee-jerk reaction to reading this, but alternatively, this could instead be read you regain HP equal to the necrotic damage done by the attack. What do y'all think?