Let's Dub Pokémon FireRed
Cryshulvo for Koga
The Gym Leader of the Fuchsia City Gym. He specializes in Poison-type Pokémon, and gives out the Soul Badge to any Trainers who beat him in battle.
Fwahahaha! A mere child like you dares to challenge me? The very idea makes me shiver with mirth! Very well, I shall show you true terror as a ninja master! Poison brings steady doom. Sleep renders foes helpless. Despair to the creeping horror of Poison-type Pokémon!
Humph! You have proven your worth! Here! Take the SoulBadge! Now that you have the SoulBadge, the Defense of your Pokémon rises. It also lets you Surf outside of battle. Ah! Take this, too!
Sealed within that TM lies Toxic! It is a secret technique dating back some four hundred years. When afflicted by Toxic, a Pokémon suffers more and more. It suffers worsening damage as the battle wears on! It will surely terrorize foes!