Avatar: The Burst Warrior and The last Airbender.
pokemon x avatar
self insert burst warrior(with multiple Burst hearts, collects more through out story, starting with Zekrom and Pikachu. air temple: Passimian and Buffalont

later burst warriors
Maya(9 y/o): Noibat/Noivern
Sokka: Riolu/Lucario, Braviary(boomerang air slash)

Using Zekrom can be dangerous, just like with any legendary pokemon

Secret tunnel: Drilbur(compatible with either oc or Toph)