Undeath passive requires stage 3 Vamp. When Undeath had its mitigation at a max of 30% it kind of made sense that stage 3 took the additional flame damage it takes. However, with the nerf to undeath, it has thrown this balance out of alignment. Details from ESO Skillbook below. At stage 3 I take 16% additional flame damage.
16% damage is broken for two reasons that I can think of:
1. 16% increase is additive and always on. undeath scales with missing health. This means that, no matter what my health is, I'm taking extra damage from anything and anyone with flame damage in pve and pvp. My mitigation doesn't even get close unless I'm in execute range.
2. The damage increase is additive and the mitigation is multiplicative. This means that if I get hit for 10k flame damage, I really get hit for 11,600. It is just added. However, the mitigation only applies to the percentage of damage I haven't already mitigated. For example, if I'm at the mitigation cap of 33.5k resist I get 50% damage reduction. This means I'm exposed to 50% of the damage. Undeath would be at best 15% of this, or 7.5% of the overall damage, and this is only when I'm already in execute range.
This is completely unbalanced I would ask ZOS to rework the penalties and benefits of vamp stages. I'm not asking for a buff to undeath, just that the associated penalties are reduced to be in balance.
Stage 1/2/3/4 Health Recovery: -10%/-30%/-60%/-100% Flame Damage Taken: +5%/+8%/+13%/+20% Regular Ability Costs: +3%/+5%/+8%/+12% Vampire Ability Costs: -6%/-10%/-16%/-24%