I wasn't sure how to send in this idea, and I don't know if anyone else had given this idea.
I thought it might be a good event suggestion for a Shurima based one similar in nature to the Wolves vs. Lions and the old Ascension game mode. This could reveal two Ultimate or Legendary skins focusing around Azir and Xerath.
These skins would focus lore wise to the rise of their ascension, leaving them to change similar to Pulsefire Ezreal's change as the match goes on. Perhaps their actions, may it be through supports or kills, would allow for different paths of Ascensions. Xerath could potentially reveal what could have happened if his ascension hadn't failed, and Azir could have changed into something akin to Xerath's failed transformation.
Similar to past events as of late, the Event Medallion could be shaped like Azir's Sun Disc, and if Xerath and Azir enter the match it could lead to an in-game quest akin to Ashe and Sejuani's. However it would be focused on who can ascend first and or who claims dominance of Shurima.