Cobalion

Cobalion is very diverse, being able to attack or support with equal efficiency given its well-rounded stats. Its dual base 90 offenses and great Speed combined with its access to Swords Dance and Calm Mind means it is perfectly equipped to sweep both physically and specially. Its Steel / Fighting typing gives it a STAB attack to deal with Fairy-types, which few other Fighting-types can boast. It also gives Cobalion a resistance to Dark-type moves, which combined with its fantastic Defense stat and ability Justified makes Cobalion an excellent Knock Off absorber. Furthermore, Cobalion is 4x resistant to Stealth Rock and immune to Toxic Spikes, which makes it easy for it to switch in multiple times throughout the match.

On the downside, base 90 / 90 offenses are average at best, so although Cobalion is capable of boosting both, it lacks significant immediate power. It is also hampered by a poor base 72 Special Defense and weaknesses to common attacking types such as Fire, Fighting, and Ground.