Troll's Vitality

You or another creature within 15 feet that you can see is endowed with the regenerative abilities of a troll.  For the duration, at the end of the target's turn it regenerates 1d6 HP.  If the spell is cast on an undead creature, the creature instead takes 1d6 damage.  If the target has 0 HP at the end of its turn, it does not regain the HP, but does automatically succeed on a death save.  This spell cannot be cast on a creature that already has 0 HP. The target cannot regenerate (or take damage from the spell) if it takes fire or radiant damage during its turn.  This spell regenerates an additional 1d6 HP for every odd level above 2nd.  If cast at 5th level, the spell can additionally target 2 creatures, and if cast at 8th level can target 3 creatures.