Lifegiver

Perk Lifegiver
Requirements	Level 12, Endurance 4
Ranks	2

With each level of this Perk, you gain an additional 4 Hit Points every time you advance a level. This is in addition to the hit points you already gain per level based off of your endurance.

This perk should take earlier as you can, because you gain more HP per lvl.
Note: "every time you advance a level" AND once right after picking this perk.