Vesper Primer+Constant Effects+Hard to Kill

Whenever you’re below 0 hit points, you automatically stabilize without needing to attempt a Constitution check. If you have an ability that allows you to act while below 0 hit points, you still lose hit points for taking actions, as specified by that ability. Bleed damage still causes you to lose hit points when below 0 hit points. In addition, you don’t die until your total number of negative hit points is equal to or greater than double your Constitution score.