Ashen Renewal

The creature you target gains temporary HP equal to the HP it lost by the triggering effect.  An unconscious creature may choose to regain consciousness while they have the temporary HP from this spell.  Creatures at 0 HP must still make Death saving throws as normal, though they may also spend their action attempting to stabilize themselves following the normal rules for stabilization.  The afflicted creatures wounds appear to fill themselves with shadowy ash.  If this spell is concentrated on for the full duration, the remaining temporary HP becomes regular HP, up to the target's max HP.