Too bad that Garchomp's Mega form gets a small decrease in its Speed because some Fairy-, Dragon- and Ice-types can have a big advantage on it even though it has high attack. Anyways, Garchomp is a great physical attacker and Dragon- / Ground-type for your team, poor Electric-types don't even have an advantage because of Garchomp's typing unless it knows Hidden Power [Ice] and then you are screwed. In this set it'll make it fast and very offensive as if it already has the perfect IVs for attack and speed or as if it had both an Adamant and a Jolly nature!
Garchomp @ Rocky Helmet / Choice Scarf
Ability: Rough Skin
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Dragon Claw
- Earthquake
- Iron Head
- Stone Edge (if you are going with the Choice Scarf) / Swords Dance (If you are going with the Rocky Helmet)
With a Jolly nature, Garchomp will be faster than usual. With Rough Skin paired up with a Rocky Helmet, it would do serious damage to the opponent if it has a contacting move, or you can Scarf it with a Choice Scarf and make its great physical moves monstrous. Dragon Claw is for STAB, great power and perfect accuracy, Earthquake is also a STAB move and has the perfect accuracy and hits a lot of your opponents, but also your allies in Double or Triple Battles, but it's still a great move. Iron Head is for coverage against those big mean sneaky Ice types, and those pesky Fairy types, and it has 30% chance of causing a flinch. Swords Dance raises Attack by 2 stages or you can go with Stone Edge for greater power and a small chance of causing critical hits.
READ THIS: Just so you know, Iron Head is an egg move so you may have to do a mating spree with your Garchomps.