I think new guildhests would be a great idea. They could make each guildest based on various different mechanics introduced in new and previous ex fights. Each guildhest could contain 1 or 2, maybe 3 mechanics at most, and that would be great way to practice. How many different mechanics each ex trial does have? Like 10-12 or so? Why not break them down and put them to like 5 guildhests for easy learning?