Fire Red - Charizard (Level 70's) + 5 random pokemons (Level 20's-30's) Used them to ressurect charizard. Charizard is beast soloing the elite four. Kept going like this until Pokemon Diamond where I added a lucario and inferno.
Got lost, leveled my starter until it evolved once, beat the rival with a single Razor Leaf, realized what I'd done and restarted.
First team to beat a game with:
Typlosion bunch of lower-leveled Pokemon
I had a guide this time, so I knew where to go. I also was very good at type matchups. Unfortunately, I had no idea how to properly raise a team, so I soloed the game with my starter.
I also had no idea how to revive fainted Pokemon or even heal them, so I basically played like a strict Nuzlocke, only instead of my Pokemon dying, I would restart from my last save whenever my starter fainted. After many tries, I beat Red with only a level 86 Typlosion that I had used the entire game. Two of its moves were Flame Wheel and Thunderpunch, but I forgot the other two.
First team to get to level 100 (this may have also been my first team raised correctly, although I'm not entirely sure):