i don't know if he'll become a major character or not but dad(dy) material
zhongli is the main god of dragons, the gold of gold, and contracts. there are a few more gods dragons worship but he is the main, especially Ky's clan.
zhongli's problem child xiao: a god in his own right sworn to protect ky's clan specifically from outside harm.
Wei Wuxian if the gang somehow revive him (Or Michael does when he discovers what the amulet is to bring him on his side)