In Pokémon Shining Diamond and Shining Pearl, the first gym that your strongest starter Pokémon is likely not to be troubled by is Maylene's Stonevelo Gym. The entire building is themed and chock full of combat types, a group known to have very few weaknesses. Maylene's Pokémon also maintain this theme, but are much stronger than the others you'll see in the gym. While this is the first real uphill battle for coaches, there are a few tactics that will easily earn this gym badge.
What are Maylene's Pokémon?
Fortunately, Maylene only takes out three Pokémon during this great fight. The order of the Pokémon used is as follows: Meditite (Lv. 27), Machoke (Lv. 27) and Lucario (Lv. 30). Despite its level, Meditite shouldn't be a problem, as it only has Drain Punch as its only attack move. On the other hand, Machoke's two attacks are rock-based Bulldoze and Rock Tomb, with Lucario capable of performing Drain Punch and the terrifying Metal Claw.
As you can probably imagine, Maylene will use two Super Potions at some point, typically only on Lucario. That said, the key to beating Maylene is having a Pokémon that is super effective against Lucario. The sooner Lucario is off the pitch, the less you will have to continually fear him using Metal Claw.
The best Pokémon to use in the third gym
The most effective types against Fighting types are Fairy, Flying, and Psychic. Since Maylene's Pokémon also have some steel attributes, some Fire-type moves might deal extra damage. Trainers are very likely to discover these types of Pokémon through the different biomes in the Underground Huts.
In biomes, players should find and capture a Psyduck that is, it maintains a level in the mid-20s. While it's a great catch overall, you'll need it due to its powerful Psybeam attack. Being a Psychic-based move, a single psychic beam should take out Maylene's Meditite and Machoke.
To defeat his Lucario, focus on catching and leveling a Fire-type with Ember or Flame Charge. Some may see these moves if they wish Chimcar as their appetizer. Otherwise, ponyta makes an excellent replacement, as it also learns both. Ponyta can be caught on route 210 and should be around level 20.
You've heard of fighting fire with fire, right? Well, you may want to fight combat types with combat types. One of the best and most common catches anyone can discover in the Grand Underground is a level 25 machop. Any damage from Maylene brought to Machop will be almost miniscule, giving the Pokémon time to increase its attack stats. When this is done, Dark-type moves like Knock Off should prove volatile.
Related: How to enter Veilstone's Galactic Headquarters in Pokémon Brilliant Diamond and Shining Pearl