Watchful Sentinel
Watchful Sentinel (monk only) is a class-restricted feat. Protect your allies from ranged attacks. Mechanic: When a creature within 5 feet of you is attacked by a ranged weapon attack, you can use your reaction to use your Deflect Missiles ability on behalf of the targeted creature.
Prerequisites
Only monks may take this feat
Limited to: Monk
Description
When a creature within 5 feet of you is attacked by a ranged weapon attack, you can use your reaction to use your Deflect Missiles ability on behalf of the targeted creature.
This is a relatively small benefit. Talk to your GM: they may be willing to combine this with another defensive feat.