Looking for an old map with rotating rings...

[Sirpenrose]

I know this is a long shot, as I've been trying to find this map since like 2007 and it's probably gone to the data graveyards, but here goes--

I'm looking for an old duel (possible multiple gamemmode?) map with a name something like "EoS_duel". EoS seems to ring a bell for me, but I can't be sure what the acronym was. The map consists of a cel-shaded platform made of blue glass and black structure with a set of rotating rings, like a gyro rotating around it. The platform is floating in a grey void, but there was also a different variation included showing more of the same platforms floating in a cloudy orange skybox.

The map also has the song Session by Linkin Park playing on it.

Any help tracking down this old upload would be greatly appreciated.