The defender has a number of Hit Dice [d8s] equal to your Artificer level.
Steel Bond. Add your Proficiency Bonus to any ability check or saving throw the defender makes.
Force-Empowered Rend. Melee Attack Roll: Bonus equals your spell attack modifier, reach 5 ft. Hit: 1d8 + 2 plus your Intelligence modifier Force damage.
Repair (3/Day). The defender, or one Construct or object it can see within 5 feet of itself, regains a number of Hit Points equal to 2d8 plus your Intelligence modifier.
Reactions:
Deflect Attack. Trigger: A creature the defender can see within 5 feet of itself makes an attack roll against a creature other than the defender. Response: The triggering creature makes the attack roll with Disadvantage.