What even IS Skaia? It really confuses me. Also how is the battlefield inside Skaia? Can you stand on or touch Skaia? How do you get inside? Sorry about all the questions but Skaia makes no sense to me.

Skaia is the dormant crucible at the center of the session that is made of dense clouds that show past, present, and future events. The planet at the center of Skaia is the Battlefield which evolves with each prototyping.