Counter Attacker

When a creature you can see makes a weapon attack against you or your ally within 15 feet of it, you can attempt to block the damage from that attack. You can use your reaction to immediately move up to half your movement speed and make a single weapon attack against that creature directly before it's attack. If your attack hits the target, instead of dealing normal weapon damage, you can choose one of the following options:

Deflecting Blow. Subtract your attack roll total from the target's attack roll potentially causing it to miss; if you reduce the target's attack roll to zero or below, the target must subtract 1d4 + 1 to the next attack roll they make.

Glancing Blow. You can reduce the target's damage from it's attack by an amount equal to the weapon damage you rolled; if you reduce the damage to zero or below with your attack, the target then receives any left over damage.

If you decide to use either option, you must call out that you do so before you make your weapon attack.