Warding Aura of Undying

When you finish casting this spell at the end of your turn, an aura of warding extends 30 ft from the point where you are standing. Choose aberrations, beasts, celestials, dragons, fey, fiends, giants, humanoids, monstrosities, or plants to be effected  Until the start of your next turn or until you lose concentration, whenever a creature of the chosen type, within the spell effect radius, would drop to 0 hit points, they instead drop to 1 hit point.