>>20127250>RivalI would basically be introduced at the first town you enter, not the starting one. I would be blocking the way ono the next route until some event takes place, when that happens I appear out of nowhere and swipe an important item and talk in a mocking tone.
Battle challenge commences against my swinub and if I lose then I give the stuff back keeping true to the deal and think you're an alright person, of course i'll still throw you some slack every now and again. After that i'd appear after every gym or two for a battle with some snarky comments, give some tips on some things and take my own path until villains hang about.
I help on taking down the antagonists mainly by distracting most of them with my starter, and the protag goes for the final boss.
After you beat the elite four and champion, I come walking in before you enter the register room and challenge your champion status instead of the other way round.
Final team would be:
Tentacruel
Gallade
Magmortar
Heliolisk
Durant
Mamoswine as the ace
all starters are SE against it and vice versa barring water 