Megas to High Ladder team for ya. Mega Heracross under Trick Room is all you need, a 185 Atk stat is disgusting.
Bullet seed/earthquake are also options, however SD helps break pex and the like:
https://pokepast.es/4b14b585d5769a6b
Bullet seed/earthquake are also options, however SD helps break pex and the like:
https://pokepast.es/4b14b585d5769a6b