I've got a few!

Organizing them by region:
Mondstadt - Rhein (Hydro)
Liyue - Xuĕ (Cryo), Jiang (Dendro)
Inazuma - "Beltrame"/Yōko (Electro Delusion, Pyro Vision)
Sumeru - Nadine (Hydro)
Snezhnaya - "Mezzetino"/Wei Yang (Geo Delusion, Pyro Vision)
Fontaine - Eliás (Geo)

Fun fact, only Nadine is the OC in this list who isn't shipped with a canon character.