Coalissia

Coalissia is a realm entered from the portal room with a 130,000+ level requirement.

This realm is in stages, with each stage needing 30,000 more level then the previous to enter, each section having 3 enemies of that style (for example, "light coalis, ancestor grass coalis.)

And the boss of the same type. (needing 30,000 more levels then the previous) that you fight to go to the next stage.

I am unsure of exactly how many sections there are, because I am still going through it, but after you beat the final boss section im pretty sure you get a coalissia's key, to unlock the ancient which i think is the final boss of the realm.

So far I have encountered 7 sections, plus the ancients area.

It is the previous realm to 8-bit.