You’ve developed the skills necessary to hold your own in close-quarters combat and forced movement such as grappling. You gain the following benefits:

• You have advantage on (STR) Athletics checks.
• You can use your action to try to pin a creature grappled by you. To do so, make another grapple check. If you succeed, you and the creature are both restrained until the grapple ends.
• Increase your Strength or Dexterity by 1.
• You can use an unarmed strike as a bonus action against creatures you've grappled or pinned (restrained).
• Unarmed strikes against creatures you've grappled or pinned (restrained) use 1d6 + your strength modifier.