A Au of Inuyasha that has pokemon existing in universe. Kagome has a Chimecho and a Arcanine from her grandpa, and she caught a Cyclizar during a trip to Paldea.

Si character has a Interface(those float screens from gamer fics) that acts as a pokedex and inventory(as well as instructions, like in legends arceus for item crafting) as well as a PC, which just a pocket dimension with a mildly large stretch of land, can plant berry trees on it.

Female Inuyasha as usual, as well as Sesshomaru(who dresses similarly to a man) who happens to have a twin sister.

Much like in legends arceus, Si will introduce how pokemon can live happily with humans, and helps the village, introducing pokemon to help.
He would show up in the past 2 months before Kagome, meaning he'd have helped the village adapt to pokemon enough by the time She gets there that they can fend off the more malevolent yokai.

Original Regional variants
Heian Gurdurr(ghost/fighting type)(the girder it usually holds is now a wooden pillar) known to build resistant structures and especially buildings that can ward off evil spirits and disease, most known for building Shrines and Temples.

Heian Ghastly, Haunter, and Gengar (Ghost/Fire) born from sorrow of being alone and lost, these pokemon light the path for those who have lost their way, and guide them to safety.

Heian Venipede, regional evos Curlipede and Yomipede
(Bug/Poison- Bug/Dark) Curlipede becomes a flater and longer Venipede that rolls in on itself, and Yomipede becomes a more centipede version of Scolipede, with a extended out head and frontal mantis like claws, to mimic (what ever youkai lady centipede is)