Is this on emulator?

Nope, I'm running on an New 3DS with an internal capture card from Delfino Customs.

Why Mudkip over Treeko or Torchic?

Mudkip can learn four HMs that we need to complete the game, and generally wrecks house once we get Bulldoze in Mauville City.

Why do you keep resetting on Rival 1?

Most Mudkips don't have high enough IVs to survive the route. At level 6, we need at least the following stats:

14 Attack
10