Been testing a pretty cool core of Genesect / Forretress / Dugtrio and it works amazing. Genesect forces a lot of switches in combination with Forretress's hazards is an easy way to rack up damage. Genesect also gets free switches into Dugtrio, as Dugtrio does not want to take a hit with it's very pitiful defenses. Forretress also provides Rapid Spin support which is essential as these three Pokemon will be switching a lot to force momentum, and trap threats that stand in the way of Genesect. This is especially effective against weather teams, most notably Sun and Sand as both survive a U-Turn from Genesect but are trapped but Dugtrio, essentially winning you the weather war.
Genesect @ Choice Scarf
Trait: Download
EVs: 88 Atk / 168 SAtk / 252 Spd
Hasty Nature (+Spd, -Def)
- U-turn
- Bug Buzz
- Ice Beam
- Thunderbolt
+
Dugtrio (F) @ Focus Sash
Trait: Arena Trap
EVs: 252 Atk / 252 Spd | 0 Def / 0 SDef
Hasty Nature (+Spd, -Def)
- Stealth Rock
- Memento
- Earthquake
- Reversal
+
Forretress (M) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 176 Def / 80 SDef | 0 Spd
Relaxed Nature (+Def, -Spd)
- Gyro Ball
- Volt Switch
- Spikes
- Rapid Spin
It's not just weather inducers that Dugtrio traps, it's more or less the main switches / common resistances and checks to Genesect, making it a lot easier for it to sweep. Combine this with hazards and Genesect really is a force to be reckoned with. Forretress is there to spin away hazards keeping Dugtrio's Focus Sash intact, while also guaranteeing a slower Volt Switch against pretty much everything in OU. This means you get another free switch into Dugtrio / Genesect, whether it be to trap or rack up even more hazard damage on your opponent.