Explosive Tank.

When the guard dies, or if it rolls a 1 when checking whether its Scorchbringer action recharges, the tank on its back explodes in a 10-foot radius sphere. Each creature in that area must make a DC 12 Dexterity saving throw, taking 7 (2d6) fire damage on a failed save, or half as much damage on a successful one. The explosion ignites flammable objects that aren't being worn or carried, and it destroys the scorchbringer.

Actions

Light Hammer.

Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 4 (1d4 + 2) bludgeoning damage.

Scorchbringer (Recharge 4–6).

The guard's scorchbringer spouts a stream of flame in a line that is 30 feet long and 5 feet wide. Each creature in the line must make a DC 12 Dexterity saving throw, taking 7 (2d6) fire damage on a failed save, or half as much damage on a successful one.

Scorchbringer Guard