Some remains of an ancient Tkzeph dyson swarm were re-used by the Black Acropolis Builders inside their habitats
Vast expansionist theocratic/(?)aicratic starfaring empire that disappeared without a trace some 312 million years ago. The existence of this empire is only known from stories and legends told by the Muuh, the Soft Ones, and others.
According to these stories the Tkzeph had a wormhole nexus far larger than the current Terragen one. Estimates put their maximum expansion at 38% of the galaxy. However no trace of these wormholes have been found, and some xenoarchaeologists doubt that they existed. The Tkzeph vanished after a conflict with another contemporary race, the Hov's'sa, who are almost as mysterious as the Tkzeph.
Only a few remnants of their great orbital rings and dyson spheres still exist, pulverised into almost featureless dust by collisions. One dyson sphere apparently built by the Tkzeph remains in use, the Black Acropolis, but it has been heavily modified by later civilisations such as the Ultimates.
No intact Tkzeph ship, database or functioning technology has been found. However any relic of this vanished race has considerable market value because of its rarity.