You have practiced, trained, and have turned yourself into a living weapon. While you have an enemy in your grasp they are completely at your mercy.

Shove a Grappled Creature. You can attempt to Shove a creature you are grappling as a bonus action.

Moving While Grappled. You can attempt Moving a Grappled Creature, even while Grappled by that creature, as long as you have no other restrictions on your movement. As a bonus action you can make a contested Strength (Athletics) check against the target. If you succeed, you can move up to half your normal movement speed this turn.

Opportunity Grapple. When a hostile creature’s movement provokes an opportunity attack from you, you can can use your reaction to make a Grapple attempt against the creature, rather than making an opportunity attack.

Return Grapple. Whenever you are the target of a Grapple attempt made by a creature within 5 feet, you can immediately use your reaction, to attempt to Grapple that creature.