The vectorian is an Arcam mothership that acts like a rerouter for Arcam Probes, which enters slipspace so that the arcam's can get to the other Universal Rings. so that they can create Warp Gates that can open portals to Carrianus

Arcams Protect this mothership by allowing enemy ships to get close to the tugs which bring towards the Vectorian and once in range the Corvettes Blasts their Plasma Wave Cannons at the threat until its destroyed