Volt Absorb Impish Pachirisu@Sitrus Berry, with EVs to make it a wall: Pokemon didn't post that. Nuzzle Follow Me Super Fang Protect
The crux of this set is Follow Me, which redirects moves from your sweeper to the surprisingly tanky Pachirisu. This doesn't work in Single Battles, and in Double Battles, it won't have the element of surprise that made it that good in VGCs. For a few months, everyone playing Doubles at a remotely high level will overemphasize Ground-types, Electric-types, Limber Pokemon, Ghost-types, and normal Rotom as they counter this set to an extent (blocking the Nuzzle paralysis, the Super Fang, or both). So Smogon singles won't care about this set because it is NOT a singles set, and Smogon Doubles won't care about this set because it HAS counters; people just didn't carry them because this wasn't a thing until he came up with it.
Generation (pi)(i). When you see this, raise e to the generation and add 1. Social experiment.