The Neon Gods
Laugh all you want. When was the last time the Monoliths or Sovereigns responded to your prayers?
One of a Kind
Warden, Foster, Anthem—You'll never see Engines like them again. There was a special chemistry to the teams which breathed life into them, a chemistry destroyed by the ravages of time and differences of opinion. Some of our greatest philosophers, scientists, engineers, and neurologists collaborated to create the Trinity, and the events of history shaped them to mature, to spark into a higher self.
Unfortunately, much of the original teams are either long dead, or serve other Banners now. They couldn't be remade even if anyone wanted to, and no Engine made since has been so advanced as these three.