Guardian

Ability Score Improvement:

Increase your Constitution by 2 to a maximum of 30.

Humanoid Fortress:

Once per round of combat, when an allied creature within 30ft is targeted by an attack or a spell, you may expand your reaction to redirect the attack onto yourself. You will take half of the original damage if the attack hits you with this feature. This feature doesn't prevent other creatures from getting hit by any AoE effects.