Vitality Shield

You brandish your shield or spell casting focus used for the spell's casting to share your vital energy with another creature. Choose one creature other than yourself within range, for the duration of the spell, when this creature takes damage (after applying immunities, resistances and vulnerabilities), it will only take half of the damage (rounded down) but you will also take half of the damage. The damage taken by the caster through this spell cannot be reduced in any way, but also doesn't trigger a concentration saving throw. If a creature affected by this spell goes out of range, the spell end for this creature. If the spell ends in another way than by lasting its full duration or being dismissed as an action by the caster, every creature affected by this spell, including the caster takes 2d6 necrotic damage.

At Higher Levels: When you cast this spell using a spell slot of 3rd level or higher, you can target two more creatures for each slot level above 2nd. If you use a spell of 5th level or higher, the caster only takes 1/4 (rounded down) of the initial damage, but the affected creatures still only take half of the initial damage.