Serperior is the only grass type starter Pokemon that can beat a whole game by itself. I will have to fight Ghetsis, N, Reshiram, the Elite Four, and all of the Gym Leaders with only a single Serperior.

0:00 Intro
0:22 Why this challenge is hard
2:09 The first Gym and the existential horror of two little girls
5:59 The path to the third Gym
7:40 The surprisingly easy and quick midgame
12:53 I walk across the entire region twice
14:43 Path to the Champion
19:04 Dealing with Reshiram
25:13 Surprise Double Plot Twist!
26:53 Outro