Your nanites burrow into your foes, inflicting grievous injuries as they consume their victims from the inside.
When you form a cloud array or sheath array, you can use a nanite surge to damage anyone who contacts those nanites. Your cloud array deals 1d6 piercing damage (Fortitude negates) to each creature that starts its turn in or enters the cloud’s area. Your sheath array deals 1d6 piercing damage (Fortitude negates) to any creature that hits you with a melee natural weapon, melee weapon without the reach special property, or unarmed strike. After a creature attempts a saving throw against either effect, it is immune to damage from this ability for 1 minute. You are immune to the effects of your malignant mist. As a reaction, you can grant one creature you can see within 30 feet immunity to your malignant mist until the beginning of your next turn. The damage dealt by this ability increases to 1d8 at 3rd level, to 2d6 at 5th level, and by 1d6 every 2 nanocyte levels thereafter.
When a creature fails a Fortitude save against your malignant mist ability, they become infested with short-lived nanites that continue burrowing into their body. At the end of the infested creature’s turn, it takes piercing damage equal to your malignant mist ability’s minimum damage plus your Constitution modifier, after which it attempts a new Fortitude save to end the effect. This effect ends automatically after a number of rounds equal to your Constitution modifier. A creature can be affected by only a single tenacious swarm at a time.
When you use your malignant mist ability, you can make the nanites toxic in nature. Toxic nanites deal half damage to creatures that successfully save against your malignant mist ability.
A creature affected by your tenacious swarm ability is also sickened for the duration of the effect. Weapons you form with your gear array gain the nauseate critical hit effect (Starfinder Armory 31). If the weapon already has a critical hit effect, when you score a critical hit, you can apply either the weapon’s normal critical hit effect or the nauseate effect.
You can activate your malicious mist ability once per minute without using a nanite surge. You can use a nanite surge as a swift action to infect up to two other creatures you can see adjacent to any one creature within 60 feet that you can see that is affected by your tenacious swarm. The new targets are immediately affected by your malignant mist, receiving a saving throw to reduce the effects as normal.