Defender

You have become a greater party tank for your allies. You gain the following benefits:

As an action, you can provide half-cover to one allied creature within 5 feet of you of the same size or smaller than you. That creature has half-cover as long as they remain within 5 feet of you or until the start of your next turn.

Upon seeing another creature attack a creature within 5 feet of you, as a reaction, you can interpose a weapon or shield between them and the attack, increasing the target of the attack's AC by 1 if you use a weapon, or by the AC bonus of your shield if you use it. While the target's AC is increased this way, if you used your shield, you lose the shield's AC bonus until the start of your next turn. The target of the attack has their AC increased this way until the attacker ends its turn or the target of the attack moves more than 5 feet away from you.