>>58824812>fights you for floette, loses, takes her anyway despite objectively not being the strongest mega evolution user He/she is a love interest, hence the gender lock.
He/she fights you there then takes the plot devicemon anyway because he/she knows it's dangerous and can potentially backfire and harm you. Which it does.
You could say that your "rival" loves (you) too much, but the whole theme is this being the city of romance so the "rival" being head over heels for you being completely irrational with (you) in the picture absolutely fits.
(You) arrived and have no pokemon? They give you one of their personal ones.
Debt trouble? They believe in (you) being so reliable and dependable and heroic that everything will be all right as their rise tinted lovestruck glasses put (you) on a pedestal.
The tournament? They are so relaxed with (you) around they got sloppy.