Mind Control & Disruption
The Chitin Sovereignty is an insectoid civilization that rose from a single teeming homeworld and never stopped multiplying. The Sovereignty's castes handle trade, science, and war the way a hive divides labor, and the population crisis that strains the other alliances is, for the Chitin, an existential clock. Broods hatch faster than worlds can hold them. The Sovereignty does not see the new system as territory to negotiate over. It sees room, and it will take it.
The Collective is the Sovereignty's science caste, a psychic hive mind that grows more capable with every linked mind added to it. The Collective's great limit has never been intellect. It is range. Minds scattered across fortified systems strain to stay joined, and the Collective has concluded that the only way to keep growing is to keep its bodies close on new worlds of its own. A system with multiple habitable planets in tight formation is, to the Pheromind, the perfect architecture for a vast new lobe of itself.