Might of the Master. The following numbers increase by 1 when your proficiency bonus increases by 1: the defender’s skill and saving throw bonuses (above), the bonuses to hit and damage of the S.I.R. Unit attacks, and the number of hit points restored by its Repair action (below).

Vigilant. The defender can’t be surprised.

Irken Defender. In combat, the S.I.R. Unit shares your initiative count, but it takes its turn immediately after yours. It can move and use its reaction on its own, but the only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take one of the actions in its stat block or the Dash, Disengage, Help, Hide, or Search action.

If the mending spell is cast on it, it regains 2d6 hit points. If it has died within the last hour, you can use your smith’s tools as an action to revive it, provided you are within 5 feet of it and you expend a spell slot of 1st level or higher. The S.I.R. Unit returns to life after 1 minute with all its hit points restored.

Irken S.I.R. Unit Infiltraion. S.I.R Units can disguise them selves as a creature that is their size. S.I.R. Units disguises appear, feel, and sound exactly like the creature they choose to impersonate.

Assortment of Guns. Range Weapon Attack: +6 to hit, reach 80/320 ft., one target you can see is affected by one of the three following damage types Fire, Lightning, or Piercing . Hit:  1d10 + 2  fire, lightning, or piercing damage.

Missile Launchers. Range Weapon Attack: +6 to hit, reach 100/400 ft., one target you can see, automatically reloads every other round, each creature within 10 feet of the impact point must make a Dexterity saving throw, taking 2d6 + 4 piercing damage on a failed save, or half as much on a successful one. At normal range, the DC is 15; at long range the DC is 10. Hit: 2d6 + 4 piercing damage.

Taser. Melee Weapon Attack: +4 to hit, reach 5 ft., one target you can see, on a successful attack, the targeted creature must succeed a DC 15 Constitution saving throw, being paralyzed until the end of their next turn on a failure. Hit: 1d6 lighting damage.

Repair (3/Day). The Irken mechanisms inside the S.I.R. Unit restore 2d8 + 2 hit points to itself or to one construct or object within 5 feet of it.

Disrupt Attack. The defender imposes disadvantage on the attack roll of one creature it can see that is within 5 feet of it, provided the attack roll is against a creature other than the defender.