T.A.S. Endurance, a Terran Alliance Overlord
To unlock the Overlord the player needs to research Large Scale Construction, which will unlock large hulls, and all three basic weapons technologies (Beam Weapons, Missile Weapons, and Kinetic Weapons) so that there is at least one non-enhanced type of each weapon available.
Unlike the designs that focus on a particular type of weapon the Overlord does not come in any augment using variants.
This is the blueprint priorities as of Version 1.4