Gilgamesh Gold Saucer Idea
Ultros, and Typhon should get a colosseum of their own, and enlist Gilgamesh's help. Once a week, Gilgamesh would open a portal for you, revealing a monster, or character from a random Final Fantasy game. Basically you and 7 other players would be forced to participate in a multi universal trial fight. The rewards could also be glamours, so that rather than purchasing them, they could be incentives to participate for those items, in the game itself. Some of the monsters could even be notorious fights from through the series. Some even against characters that we recognize. I got this idea from thinking about the Return To Ivalice raid series. Though I'm unsure if that will actually be in that world.