Ho Oh

Massive special bulk, a nifty typing, high Attack, and elite STAB moves make Ho-Oh a threatening physical attacker that is difficult to bring down. Its typing and bulk give it opportunities to prey on Steel-types and, should it have Substitute, Blissey and throw out STAB moves that are very difficult for the majority of the tier to switch into, as most Pokemon hate getting burned by Sacred Fire or smashed by Brave Bird. Its great bulk is accentuated by the fact that many of the Pokemon that want to hit it super effectively have to do so with inaccurate moves, especially Thunder and Stone Edge. In Groudon's sun, Ho-Oh really becomes an immortal phoenix; Water-type attacks simply bounce off it, and Thunder becomes as reliable as Zap Cannon.

Ho-Oh's quadruple weakness to Stealth Rock is truly debilitating, especially in a tier where the presence of elite Ghost-types means removing entry hazards is practically impossible. This limits it to early- and mid-game play, as it will be carved up by the time the battle has nearly concluded. Ho-Oh is often used in the lead position for this reason, even if it struggles against lead Tyranitar, Kyogre, and especially Deoxys-S. Laying Stealth Rock and then forcing Ho-Oh to switch, either by threatening to KO it or by phazing it, is one of the best ways of getting meaningful damage on it. Many teams come equipped with the best Pokemon to do this, Kyogre. Kyogre, as well as Tyranitar, can also neutralize Groudon's sun, making dealing with Ho-Oh more bearable. Winning the weather war makes the coverage used to super effectively threaten Ho-Oh more impactful as well.