>>43922408some elaboration. Mustard said she has natural potential/skill but because of this she’s lazy about it and coasts on it rather than actively working to better herself. You beating her snaps her out of this mentality as she starts putting in the effort to become better than you.
Eg- 2nd challenge where the whole dojo couldn’t find mushrooms except you: she tries to battle you for them, loses and doesn’t want to lose face so she puts in the effort to find some by herself at the last minute.
3rd battle she gets to the arena early and rigs it with poison spikes. (Game says cheating, I say proactive thinking though not very sporty but since your teams’ godlike, fair enough)
Anyways, good rival, enough frequent contact and character that I remember who they are next time I meet them this time round. DLC is shortish but an improvement over the base. Esp map design.