Ho Oh

Thanks to its astronomical bulk, 32 PP Recover, and good defensive typing, Ho-Oh makes for a very good wall capable of checking important Pokemon in the metagame like Mewtwo, Steelix, Gengar, Heracross, and non-Rock Slide Mew. It's also capable of phazing Pokemon like Curse Snorlax in a pinch thanks to its decent physical bulk. Access to Toxic helps Ho-Oh put Pokemon that would otherwise check it, like Tyranitar and Zapdos, on a timer. Ho-Oh also functions as a good lead on teams, as its massive bulk and the rarity of enemy leads that can threaten it such as Zapdos let it scout and gain information about the opposing team without much trouble while still applying some pressure itself thanks to its respectable Special Attack and Toxic.

However, Ho-Oh is very susceptible to status moves like Lovely Kiss and Toxic, as they greatly hinder its ability to check the Pokemon it's supposed to check. A complete inability to get past Tyranitar means that Ho-Oh teams oftentimes find themselves having to deal with Roar + Spikes, which can wear Ho-Oh's team down quickly. Ho-Oh can also be lured out by Explosion from Mewtwo, Mew, and Gengar, all common users of the move and Pokemon Ho-Oh regularly switches into. The prevalence of Growth + Baton Pass Pokemon like Jolteon also hurts Ho-Oh's ability to check the Pokemon it's supposed to, like Mewtwo, as Ho-Oh can no longer switch into them if they have been a passed a Growth boost.