A while ago during my Sketchtember escapade, I made yet another AU with Highlands shipping as somewhat of a focus, but mostly it's like this:
Cresselia and Giratina posses Melli and Ingo respectively and they get into such shenanigans that Dialga and Palkia call up on Adaman and Irida to essentially tell them "Guys, they are too silly, you need to stop them because if we were ti come and do it, we would just beat our sibling into lasagna and your region would be gone so please deal with our f- up."
1. Acting very out of character yet making everyone in Hisui believe that they are the people they are pretending to be.
2. Deciding to go on a vacation to Unova to see their old friend Victiny.
3. Adaman can't use a map for the life of his.
4. The legendaries channeling their powers through full! Pokéballs just to make the Pokémon in them match their aesthetic.
5. 2 people being so gay for eachother, they almost make the 2 legendaries kiss.
I don't actually know how would I end the story for real, all I came up is an in character of the AU but Idk how funny ending where Zekrom just yells "DIVORCE! NOW!" and Cresselia and Giratina are forced to leave the bodies they possessed.
Also when it comes to the Pokémon, I'm actually thinking about drawing that for real and even got like... A gimmick for these forms.
For Melli's Cresseliad Pokémon it's that they get bulkier (more HP + 1 of the defences boosted + they can still attack while using Rest).
Ingo's Giratinad Pokémon would actually mimic what happens when Giratina changes form and simply put, the offensive and defensive stats swap.