Okay, it's been slightly touched on in this thread, but Kartana is absolutely absurd. The only way for it to die is if it gets outsped and nuked with a special attack.
http://replay.pokemonshowdown.com/azure-gen7pokebankubers-27286
(skip to turn 10)
My Kartana had a band and all I needed to start my sweep was to slightly weaken a pokemon (in this scenario landorus) into range of being KOd. It can instantly demolish ground, and though I have yet to try it on the other types that it's stab beats, I assume that it would be the same against them.
http://replay.pokemonshowdown.com/azure-gen7pokebankubers-27286
(skip to turn 10)
My Kartana had a band and all I needed to start my sweep was to slightly weaken a pokemon (in this scenario landorus) into range of being KOd. It can instantly demolish ground, and though I have yet to try it on the other types that it's stab beats, I assume that it would be the same against them.