Time to reveal some info about the Latimas Au, but firstly here is Rei and Akari in the Latimas Au, Rei is a Johto Sneasel and Akari is a Hisuian Sneasel, they are twin siblings in this Au.

Okay NOW on to Latimas AU story bit’s

Story beings during PLA era with Rei and their twin Akari being defeated by Volo
Volo steals the plates from them and as they are trying to stop Volo from recreating the world, something happens/goes wrong and humanity gets Thanos snapped instead.
For Rei and Akari they don’t know this has happened, all they saw was a blinding white light and suddenly they are waking up on a mountain in future of this ‘New World’ in Unova - (But its Pokemon Mystery Dungeon style)
They wake up to find that they are Pokemon, Rei is now a Johto Sneasel while Akari is a Hisuian sneasel
The story from their is them getting their bearings and trying to 'Fix’ the world to what it once was as really bad stuff is now happening and the world could be ending if its not stopped. While meeting some familiar faces along the way.
Rei and Akari actually encounter Lati-Emmet first as he and his recuse team were on a mission on the mountain they wake up on.
So yeah the Latimas AU story starts with Rei and Akari and not Lat-Ingo and Lati-Emmet, but both set of twins are main characters to this Au