One thing I am thinking about lately is the "climax" (storywise, not what you think

) at the end. A final fight where one side takes all of the gems of doom between Orion (+ the girls?) and Thanatos seems obvious. But I don't think Thanatos will be the "end boss." First of all, a 8v1 seems pretty lame as the grand final. Second of all, how long can you stretch such a fight? 5 minutes? Maybe 10? I don't think Caribdis build the game of years and years to end it with a fight like this.
In my opinion, in the end we'll get a fight like in Harry Potter 7.2. Two big armies, WRE + all the allies we made through the story (the werewolves / vampires, probably the elves, characters like eve and maat etc.) against some other army.Maybe Thanatos will be part of this army, maybe he'll be already defeated before and we fight against the founder or the aliens (forgot their name) but this seems like the most likely climax. I'd bet that the fight will be in a few different servers aswell, making full use of eternums world building.