Interestingly you can also reasonably match up some of the areas in the dungeon and zone with Meteion's report back in Elpis;

The Pestilent Sands area with the fish people seems to match her description of Tessera:
"Edifices surmised to be abandoned residences found. No Extant life-forms detected. Deadly plague or extreme environmental degradation likely to have led to mass extinction".
Judgement Day may be Okto:
"Star found in state of violent conflict. Contact succesfully made with inhabitants, but deployment of weapons of mass destruction resulted in total annihilation of local population shortly thereafter".
The Nekropolis area at the end of the Ultima Thule may have been Hena:
"Traces of civilisation found—structures believed to have served as domiciles. No extant life-forms detected".