Determination, the key of life. I will open the door to my companions. Keep them safe, keep them strong, keep those I care for alive, this I my motto. If the world sent the Reaper of Death to torment one creature then let it be me. For I will not even break underneath death's judgement. If I am alive, then death cannot touch me.

"The Selfish will only use the world, but the Kind will only care for the world" -Guardian Angel, the hero of Red River Valley

Once per long rest you can become "Determined" and gain multiple effects (this feat can stack with other "Will of" feats)
For 6 hours you gain temporary hit points equal to Constitution modifier for every successful hit targeted on you. If you are going to fall to 0 hit points and become unconscious, instead you gain hit points equal to your level and remain conscious, but you may only use that effect once during the 6 hour duration. After the 6 hour duration your Maximum hit points are halved until you take a long rest.