Stalwart Defender

You live and fight by the ideal that if someone wants to harm your allies, they are going to have to go through you first. You gain the following benefits:

• When a creature within 5 feet of you would make an attack against a target other than you (and that target doesn't have the Sentinel feat), you may use your reaction to make a melee weapon attack against that creature when they announce that attack, but before they make their attack roll. A successful hit by you imposes a disadvantage on the triggering creature's attack roll against their target.
• Anytime you would make a melee weapon attack, and your target is no more than one size category larger than you, you may instead use your shield to shove your target. If this would replace an opportunity attack, your target's speed becomes 0 for the rest of the turn.
• If a creature within 5 feet of you is subject to a Dexterity saving throw from a spell or harmful effect and you aren't incapacitated, you can use your reaction to add your shield's AC bonus to that creature's Dexterity saving throw. This can be used after the roll is made, but before the results are determined. Creatures that are already receiving a shield's AC bonus to their Dexterity saving throws cannot benefit from this.
• If you take the Attack or Dodge action, you can use your bonus action to move a willing creature within 5 feet of you to another space adjacent to you. This movement does not provoke opportunity attacks.