Initially this was just a HO gimmick team for BDSP OU but it's actually pretty solid (peaked around 1500, though I'm not the best player). Basically, suicide lead Skarm to get up hazards, Taunt on Gengar, Zam, and Skarm to prevent opposing hazards/defog, then chip down the opposing team until some form of priority can sweep.
https://pokepast.es/ea7d4895dc782d9a
https://pokepast.es/ea7d4895dc782d9a
https://pokepast.es/08188ab3e37d34de