Seth is kinda like Yosuke and Valkenhayn in the rushdown mixup department, so you might wanna look into him.
Rachel and Yukiko, ehh theres no one thats rly like em. The main zoner characters are Vatista and Hilda.Hilda relies on her really long ranged normals, but has a weak up close game, Vatista is a pretty good zoner and has a decent mixup, plus her damage output is pretty high. She does have some charge moves though so her execution might be higher.
I dono how Robo Ky plays but if you wan't someone like Ky, I guess Hyde is the way to go. He's the go to protag with decent range, whos all around balanced.