Boon of the Dark Vanguard

For each Death Rune, you gain a +1 bonus to AC and attack rolls. Whenever a creature is reduced to 0 Hit Points within 120 feet of you, you may use your reaction and expend a Death Rune to have them instead be reduced to 1 Hit Point. As a bonus action on your turn, you may expend a Death Rune to gain the effects of the Death Ward spell.

At two Death Runes, you may choose an additional rune from your Runecrafting feature to apply to your weapon. You may apply another rune once you reach four Death Runes.

At four Death Runes, your Antimagic Shell has evolved to safeguard you from any harm. When you form the shell and at the start of each of your turns the shell gains an amount of hit points equal to your amount of Death Runes times 10 up to a maximum of your max hemocraft die times the maximum of your hit die, it regains this hit points even if it currently has 0. If your shell took any damage (as in positive hp before damage) any excess damage dealt to your Antimagic Shell is now negated, instead of being dealt to you (it does not protect you if it has 0 hit points). It is no longer warded to protect simply against Magic, it's effects applying to non-magical attacks and abilities.

At six Death Runes, the necromantic energy fueling your body refuses to let you perish. The first time you would be reduced to 0 Hit Points, you immediately gain the effects of the Regenerate spell. You are immune to any effects that would instantly kill you, besides direct damage.