Heatran

Heatran is a very versatile Pokemon, being able to fill defensive, offensive, and supportive roles on a team. It particularly excels at stallbreaking thanks to its immunity to Toxic and its signature move Magma Storm. Additionally, its stats and unique typing are great defensively and mean that it often completely walls foes that can't deal super effective damage to it. This makes it an excellent check to common foes such as Talonflame and Cresselia, which are almost entirely unable to touch it. Its high Special Attack stat and access to Flash Fire also mean it can deal a lot of damage, even with neutral attacks. Its middling Speed stat does mean that it's often outsped by other Pokemon, however, and it isn't quite slow enough to take advantage of Trick Room. Finally, while Heatran is great defensively, it's weak to Ground, Water, and Fighting, types that are all common as STAB moves and as coverage. This means that ordinarily lopsided match-ups, such as against Charizard and Scizor, can be a risky proposition when Focus Blast and Superpower, respectively, are considered.