Blissey HO
I keep seeing posts how blissey is a stall pokemon. NO. Blissey is fully capable of sweeping an opponent from the start of a game, you just need to believe. Blissey is capable of making you opponent quit within 5 turns.
https://replay.pokemonshowdown.com/gen9ou-1973403731
Ps: yes yes, i know low ladder yadda yadda