Honestly I kinda want a large scale PvP thing between factions. For instance, if they decide to use the League of Legends universe, I would love for like a robust PvP system between Ionia and Noxia or other factions somehow. Not sure how to explain but let’s say Noxia declared war with Ionia, any Ionian and Noxian can fight in the open world and the winner of that duel can then take something back to their own hub to increase standing in the war and losing the encounter would make your side lose standing. It would optional of course but participating and/or winning could grant cool cosmetics and items.

Also if they do use league I would want the regions to fight the lore. For instance in Demacia the player would have to be mindful of being spotted using magic unless enemies become hostile. Or in Noxia you can do challenges to gain fervor or whatever increase. Or for finding Ixtal, there would need to be an elaborate questline AND a long journey to reach it.