Idea 1: An item in shop that guarantee's the next wild pokemon you find is a legend but make it expensive like missingo was. Prerequisit: all gyms champions and frontiers beaten
Idea 2: Give False Swipe it's effect it has in the games
Idea 3: A map where the pokemon you run into is completely random
Idea 4: An Clan Event: Clan Tournament: each clan leader picks 3 players to join in but they must meet certain requirements
Idea 5: Event Mega Flygon: people were pretty bummed when they found out there was no mega for him in ORAS, you can even make a art contest to get good pics.
Idea 6: Underwater Map
Idea 7: Ashes Greninja
I'm sorry if any of these have already been said.