All Terrain. The tridrone can share space with creatures that are medium or smaller, and vice versa. The tridrone can also move fully or partially on a horizontal, vertical, or difficult terrain without its movement being affected.

Shield Generator. When a creature sharing space with the tridrone would be hit by an attack originating from outside the tridrone's space, the tridrone is hit by that attack instead.

Axiomatic Mind. The tridrone can’t be compelled to act in a manner contrary to its nature or its instructions.

Disintegration. If the tridrone dies, its body disintegrates into dust, leaving behind its weapons and anything else it was carrying.

Multi-Spectrum Sensors (120 ft.). The tridrone can see normally in darkness and magical darkness, can see invisible objects and creatures, and can automatically detect visual illusions and succeed on saving throws against them. The tridrone can see heat and other forms of radiation outside of a humanoid's visible spectrum. The tridrone can also "see" sound waves and vibrations. The tridrone can see through most barriers and target creatures through even complete cover (treat cover as 1 level lower than normal for the purpose of attack rolls) but is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt. Beyond 120 ft., the tridrone can see as well as an average humanoid.

Magic Resistance. The tridrone has advantage on saving throws against spells and other magical effects.

Field Promotion. When a Modron is destroyed or promoted, the nearest Modron of the next rank down is immediately compelled to upgrade itself and fill the gap. The Modron begins upgrading at the start of its next turn, and completes 1 round of upgrades at the start of its next turn after that. The upgrading process takes 1 round for each rank above monodrone that the Modron is upgrading into. During this process, the Modron is incapacitated and keeps all of its current stats and conditions until the upgrade is complete. Once the upgrade is complete, the Modron emerges in its upgraded form with full hit points and no conditions.

Teleport (Recharge 6). The tridrone teleports to a point within 250 feet that it can either see or describe with distance and direction. If the tridrone would arrive in a place already occupied by an object or a creature, the tridrone takes 4d6 force damage and doesn't teleport.

Laser (requires charge from Heat Sink ability). The tridrone fires a powerful violet laser at one to four target objects or creatures within 240 feet. Each target must be at least 10 feet from the tridrone. Each target creature must make a DC 14 Dexterity saving throw. On a failure, a creature takes 4d6 radiant damage and 4d6 fire damage and is blinded until the end of the tridrone's next turn. If multiple targets are selected, the total damage (8d6) is divided evenly among them. On a success, a creature only takes half damage and is not blinded. If a target is affected by a monodrone's Mark Target ability, the target gains disadvantage on the saving throw and the tridrone can ignore cover when targeting it with this Laser. Using the Laser recharges the tridrone's Heat Sink ability.

 Heat Sink (requires charge from Laser or Raise Shields ability). The tridrone absorbs heat from its surroundings, converting it into power. All creatures within 10 feet of the tridrone (not including the tridrone) must make a DC 14 Constitution saving throw. On a failure, creatures take 4d6 cold damage and 1 level of exhaustion. On a success, half damage and no exhaustion. Any fire in the area of effect is extinguished, and any still water is frozen on its surface, becoming difficult terrain. Using this ability recharges the tridrone's Laser and Raise Shields ability.

Emergency Data Transfer. If the Modron is destroyed by a target it can see, it can transmit all of its knowledge to another Modron within 120 feet just before being destroyed. If it chooses a Modron of lower rank, It can also give a final simple order to that Modron, which the Modron will attempt to fulfill before doing anything else, including beginning a promotion upgrade. If it chooses Modron of one rank lower, it can select that Modron as the one who will be promoted to fill its rank, even if it isn't the closest. 

Full Power to Shields (requires charge from Heat Sink ability). Until the start of the start of the tridrone's next turn, it has +5 to AC, including against the triggering attack. This ability uses a charge that could otherwise have powered the Laser ability. It provides a charge that can power the Heat Sink ability.