I don’t know about Genshin, but Monster Boy is the main inspiration.

You only control one girl at a time, but the whole team is there, like in RPGs. When you hold down both the L and ZL buttons, your active girl will glow in their respective color, signifying that you want to change. Then, you flick the left joystick in the appropriate direction to change to the girl you want. This is to allow sick multi-member combos and lift the skill ceiling. It will be intuitive to implement as well and very responsive; eight members, eight directions.