In Pokémon Shining Diamond and Shining Pearl, the first Elite Four trainer to fight is the fanatic Beetle Aaron. Despite being the easiest of the four to beat, Aaron definitely has a stronger Pokémon lineup than any gym leader. This is because the levels of these Pokemon are the highest you will still see from an opponent. Thankfully, most of them are weak to some of the more common Pokémon in the Sinnoh region.
Which Pokémon does Aaron Elite Four have?
Before getting to know Aaron's Pokémon, it should be noted that all trainers should stock up on Potions, Max Heals and Revives. You can't switch from a Pokémon in your team to a box once you pass the Pokémon League entrance, so be wise with who you choose.
Aside from your rival, Aaron will be the first trainer you face with five Pokémon. These are Dustox (Lv. 53), Beautifly (Lv. 53), Vespiquen (Lv. 54), Heracross (Lv. 54) and Drapion (Lv. 57), and will be used in that order. The first four are Bug-type Pokémon, which ultimately gives your Fire Pokémon the opportunity to thrive more in this battle.
At some point in the fight, Aaron will use two Full Reset, which removes long-lasting status effects and maximizes the health of a given Pokémon. You will need to avoid him giving it to Dustox, as the Beetle-type toxic attack can severely poison any Pokémon and will do so more often the longer it is on the battlefield.
The best Pokémon to use against the Elite Four Aarons
The smartest thing to do before fighting Aaron is to group your strongest Pokémon by making sure each is a different type. This way, you can continually switch to Pokémon that take little damage from whatever Pokémon is currently against you.
One type that definitely must be used against the Elite Four, and especially Aaron, is a Fire-type Pokémon. Of course, this won't be a problem for those who have chosen Chimcar as an appetizer. However, for other trainers, the best choice here is rapidash. If it's not in your inventory, fly to Sunyshore City and hop into the Grand Underground. Under the city, there should be more hiding places that contain a Ponyta with a level in the 50s. After being captured, he should contain overwhelmed fire attacks such as Fire Blast, Inferno, and Flame Wheel.
Another Pokémon found in this large underground area is graveler. He might be sure this (or another high-level Rock-type Pokemon) is leading the party, as his attacks are also super effective against Bug-types. Moves like Stone Edge, Earthquake, and Bulldoze can take huge amounts of HP from Aaron's Pokémon. But the main reason you'll need Graveler is its ability to learn Fire-type moves through TMs as well, turning the Pokémon into a dual-weapon powerhouse.
Since Drapion is Poison and Dark-type, most of your Pokémon will likely damage it very little. A single choice we recommend to avoid this is Garchomp, the final evolution of Gible and Gabite. The reason is that the TMs for Garchomp, such as Dig, Earthquake, and Dragon Claw, will deal double the base damage against Drapion. At this point in the game, players should discover a Gabite around level 50 in the Riverbank and Foutainspring Caves, which ultimately allows you to have a Garchomp after leveling up the Pokémon twice.
Related: How to change a Pokémon's nature in Pokémon Brilliant Diamond and Brilliant Pearl