Since zhao yen is from Ethereal plane of Ice .

I was thinking new characters is from Ethereal plane of fire maybe this Characters is Hybrid elemental be created by Mad scientists whitecoat.

he was once a human and he turn elemental fire creatures

https://forgottenrealms.fandom.com/wiki/Elemental_Plane_of_Fire

New team I was thinking Fire and ice Friends of Rivals .

Please put any idea of new characters and factions.