Name: Leif (because it sounds like leaf)
Puzzle: A gym set in the trees where you have to traverse a maze by swinging on vines.
Badge: Sap Badge
TM: Giga Drain
Once completing my maze: "By completing the maze and beating my students you have reached your final step before the elite four. Prepare yourself trainer, for a battle you won't soon forget!"
1st time taking damage: "An interesting choice, I see I might have to change my strategy with you."
Last pokemon: "It's been too long since I've been challenged like this! Prepare yourself for the pride and joy of my team!"
When I lose: "I gave it all I had, but it wasn't enough. You are indeed a very strong trainer worthy of challenging the elite four and I take great pride in awarding you the Sap Badge for your victory."