so imo non-meteor mash metagross' best use was a Machamp counter specific to Bullet Punch + Heavy Slam
Vs Bullet Punch + Heavy Slam
Zen Headbutt + Psychic Metagross has a much higher TDO than most of the non-legendary Psychic types, while still having acceptable dps and although Sky Attack Moltres and Ho-Oh also fulfill this role one is event exclusive and the other is a legendary only good in this match up and hence not worth the rare candy expense