Aegis

You summon a magical object (Aegis) at a spot within range that you can see, all creatures of your choice within a 20ft radius of this object are immune to all damage. Any damage they would be subjected to is instead taken by the Aegis. Should the Aegis be reduced to 0 hit points, the spell ends immediately.

The Aegis has 100 hit points when cast at 4th level and gains an additional 50 hit points per spell level.

When cast using a spell slot of 6th level or higher, the spell can be cast as a reaction.