Deram

Info:
Deram was a world in the Serilkis system, Thelis was one of its neighbors, it was a gateway to other realities (Reality Shift)

History:
The first recorded event in Deram's history was the war with Nightmare, a version of it in the No-Space, which led to the first extinction of the native Deramites

The Deramites were cloned (though they were imperfect, becoming the Hyisti) by the Eternals of the Eternal Space to combat the No-Space.

Eventually, it's neighbor Thelis waged war with the Hyisti, an attempt to destroy Deram was stopped by a previous regeneration of The Doctor, which Carvis was a part of.

Deram was, at some point, made into an amusement park by Galactacon, The Seventh Doctor visited with Bernice Summerfield, Ruby Galcess, and Niecytise Cnartise. they stopped the No-Space being unleashed by the Veristis (a cult started in Thelis after the Deram-Thelis war) and the destruction of all realities by a reality shift (basically a system wipe for realities) (Reality Shift)