Chromatroid Sentry

Circuit Overload. If the chromatroid sentry takes 10 or more lightning damage from a single source, its circuits become overloaded with energy. The sentry must make a DC 13 Charisma saving throw or be stunned until the end of its next turn. If it takes lightning damage again before it recovers from the stunned condition, the chromatroid sentry must then make a DC 13 Constitution saving throw or take 17 (5d6) psychic damage and become immune to this trait for 1 hour. On a successful save, it takes no damage, but can still be stunned and possibly subsequently damaged.

Innate Spellcasting. The chromatroid sentry's spellcasting ability is Wisdom (spell save DC 11, +3 to hit with spell attacks). It can innately cast the following spells, requiring no components:

1/day each: chromatic orb, color spray

Slam. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 2) bludgeoning damage.

Dash (if 30 HP or lower). The chromatroid sentry takes the Dash action.

Turn Invisible. In response to taking 30 or more damage in a single round, or being reduced to 10 HP or less for the first time in a combat, the chromatroid sentry turns invisible for 1 minute, or until it makes an attack or casts a spell.