Baldur's Shell

ALL credits to Rose knight's Homebrew on youtube

A creature you touch gains a +3 to their AC and when they are subjected to an effect that allows them to make a saving throw to take only half damage, they instead take no damage if they succeed on the saving throw, and only half damage if they fail until the start of your next turn. If the creature does not take any damage before the start of your turn they will heal 2d8 hit points. At higher levels: when you cast this spell using a spell slot of 3rd level of higher, the healing increases by 1d8for each slot level above 2nd.