Pokémon Brilliant Diamond and Shining Pearl kept several elements about the original fourth-generation games the same, but one aspect that has changed is the inclusion of Fairy-types, regardless of how limited they are.
This means Pokémon like Ralts, Mr. Mime, and several others retain their newer typings from generations post-Diamond and Pearl, giving them a leg up on certain Pokémon they might have struggled against.
Among those Fairy-types, Ralts is the most sought after, both due to its evolutionary line and because it can evolve into two distinct Pokémon with varying types depending on what you need on your team—Gardevoir or Gallade.
Gardevoir retains its Psychic/Fairy-type roots, acting as a powerful Special Attacker that can dominate numerous opponents. Meanwhile, Gallade was introduced in Diamond and Pearl, gaining the Psychic/Fighting typing and functioning as an all-around offensive option.
Locating and capturing a Ralts can be difficult since the Pokémon may use Teleport to flee a battle after just a single turn. Additionally, because BDSP is based on the original games and not Platinum, you can’t find Ralts in the wild naturally.
Instead, you will need to trek through the Grand Underground and find Fountainspring Cave, Dazzling Cave, and Stargleam Cavern Pokémon Hideways to encounter one as a rare spawn. You can also encounter Kirlia in some cases too.
Ralts evolves into Kirlia at level 20 and again into Gardevoir at level 30 without needing to use any items or other methods. Obtaining a Gallade will require you to use a Dawn Stone on a male Kirlia. You can find the Dawn Stone on Route 225, inside Mt. Coronet, and within the Grand Underground.
