Perhaps it's just the placement of the continents but I was considering that lower eastern continent more like the southern part of North America. Of course it also reminds me of the veldt in FF 6 which was like African savannah so maybe I'm just crazy.

Demorgos is fine, three syllables is kinda heavy but it could also be cool if it was elaborate, or perhaps if we corrupt it a bit more - Demgors - Dremgos - Morgos (I've definitely heard this one before) - Dromogos - Demrog -Emregos. Or more elaborate perhaps with the J/Yitou (although it sounds weird to my ear as a prefix) - Demrogos Jitous (I kinda like this one)- Demorgos Jiyou - Jiyou Demorgos...