From Halopedia, the Halo wiki
In the Covenant, ecclesiastical authorities ultimately oversaw even the most trivial modifications to existing designs. Improvements or alterations required layers of bureaucracy to navigate, and often took decades to gain approval from the Prophets. The Banished approval process is much simpler: if there is a demonstrated need and materials available a pack leader can make any changes that he or she wishes. The Wraith Invader is an example of this freedom, with Pavium taking damaged mortar tank hulls and repurposing them into heavy troop carriers.
Halo Wars 2
Wraith Invaders are exclusive to Pavium and can be made at the Banished outpost once the leader power has unlocked them. Like the Banished Phantom the Wraith Invader primarily serves as a troop transport for 3 infantry squads. It does okay against infantry, but poorly against vehicles, aircraft, and structures. In Blitz Wraith Invaders cost 100 energy.
List of appearances