So like... Who exactly were the chess people, and what was their role in the comic? IDK why, but they confuse me to no end

The Dersites(Black) and Prospitans(White) were in a war. The Dersites wanted to destroy Skaia and the Battlefield so that the players couldn’t create a new universe while the Prospitans were trying to defend it.

The Black King will always triumph over the White King. The players have to stop him before he accomplishes his goal or else they can’t win. 

They also help to spread the lore of their players and look after dreamselves until they awake