One hit and I would have beat the Elite Four dragon-dude in crystal with underpowered team. (thanks for getting me back into it r/poke)

I had a lvl 20 slowpoke with confusion, watergun, headbutt, and curse. My firetype starter lvl 38, (can't remember it's actual name(Nicknamed it)) with ember, fire wheel, quick attack, and something I don't use. Machoke lvl 38, vital throw, strength, karate chop, and low kick. Sucine lvl 40 bubble beam, rain, gust, and leer. Umbreon lvl 42, bite, take down, quick attack, and baton pass. Gyradose lvl 39, surf, dragon rage, twister, and ice wind(?) I had 11 hyper potions, 10 revives, and a 10 full heals. Last two moves, I hit charizard with bubblebeam and it slowed it's speed. I go to do it again to finish him but he still got me. I don't know why I am posting this but it is my first attempt at pokemon since yellow first came out. I am so glad I got back into it since this reddit made me want to play again. I am now 24 and married, (and drunk!) Thank you for reading and excuse the misnaming of the pokemon.