Garchomp s a Dragon/Ground type Pokémon introduced in Generation IV. Garchomp evolves from Gabite at level 48 who evolves from Gible at level 24.
Since its introduction in Gen-IV Garchomp has been the center of attention. With an impressive base 102 speed stat allowing it to out-speed most of the meta, and as a result had very few counters. Coupled with the popular Yache Berry and his Sand Veil ability left him with no solid counters, and amazing late-game sweeping capability.
Recently he has been re-allowed into the 5th generation metagame provided he does not use the Sand Veil ability. Garchomp still remains a massive threat, but with the inclusion of the Lati-Twins, the Musketeer Trio, and sturdier Pokemon he has become a more balanced force without losing too much of his effectiveness.
This set is designed to primarily capitolize on Garchomps amazing physical stats; while taking advantage of his respectable Special Attack stat to KO physically defensive Pokemon who would otherwise wall him. Of these, Ferrothorn, Skarmory, and Forretress are worth mentioning, and thankfully Fire Blast can OHKO Forretress (not counting for Sturdy) and Ferrothorn if it has 0spd investment.
When using this set it is important to keep Garchomp as healthy as possible until the end game. Focus on removing any threats to his sweep, then simply set-up and demolish whoever is left. It is well advised to keep a spinner on your team to make sure he stays at his optimum fighting power. Any Pokemon faster than him can deal at least 60% of his health, so staying above that margin is of the utmost importance.
Garchomp does not have a great number of counters, but in the even that you are locked into Outrage, nearly any Steel type can come in and do whatever they want. Although they often can't switch in easily, the Musketeer Trio and the Lati Twins are very effective at defeating Garchomp. Many Pokemon carry Ice Beam or Hidden Power Ice as way to check the rampant Dragons, and Garchomp is no exception. Consider carrying a Yache Berry if you're worried about this happening.