I think they're the best rivals, tied with the DPPt Rival for me. Great personalities, and a nice story, too. Cheren with his obsession with strength, and Bianca searching for a purpose in life... Blue and Wally only WISH they had this much development as rivals.
Bianca was quite a challenge. D8 Her tucking Musharna and Stountland, that's all.
Cheren, is hard all the way through. OTL One time I didn't even know he was gonna show up. D8 His stupid Dewott wiped the floor with me. Sob.