Gardevoir is a bipedal, humanoid Pokémon whose body resembles a flowing gown. Most of its body is white, but its hair, arms, and the underside of its gown are green. Its hair curls over its face and down the sides of its head. Behind its red eyes are short spikes, resembling a masquerade mask. It has long arms with three fingers on each hand and slender white legs. A red, fin-like horn extends from its chest, and a shorter, more rounded horn extends from the back. A band of green on its chest extends to the center of the front horn and connects to its sleeve-like arms.
As Mega Gardevoir, it turns almost completely white; only its hair remains green. Its gown becomes longer and wider, resembling a bridal gown. The forearms are slightly thicker with a pointed extension above the elbow. Its facial spikes are larger and now curl upwards. In contrast, its hair is now shorter and more tightly curled. There are now two horns in the center of its chest, extending to either side. These horns are said to be a physical manifestation of this Pokémon's heart, and it is able to use tremendous psychic power now that it is open.
Gardevoir is able to see the future using its psychic powers. Additionally, it is able to create small black holes, distort dimensions, and support itself without feeling the pull of gravity. Its power reaches its peak when protecting its Trainer, whom it will protect with its life. This Pokémon inhabits urban areas.
When summoned from a Poké Ball, it will go across the stage using Reflect to protect the summoner (and teammates) from any projectile attacks.
"An Embrace Pokémon. Despite its elegant and feminine features, there can be male and female Gardevoir. A Psychic-type, it has the ability to see the future and levitate. It's a brave Pokémon who will risk its own life to protect its trainer. It uses the ability Synchronize to pass on status problems like paralysis, poison, and burns to the foe."
Gardevoir reappears as a Poké Ball summon in both versions of the fourth iteration of the series. Once again, it uses Reflect to bounce off projectiles.
NA: Gardevoir is a Psychic/Fairy-type Pokémon, bearing an elegant appearance that male and female Gardevoir share. In Smash Bros., it uses Reflect to turn back projectiles and items launched toward it. Helpfully, it won't affect any of the shots from the player who summoned it. Take advantage of this!
PAL: This Psychic- and Fairy-type may look like a woman in a long dress, but there are both male and female Gardevoir out there! If you get one in battle, it'll use Reflect, creating a barrier that stops projectiles from hitting you and your allies. It won't block any of your shots, though, so feel free to fire all the projectiles you like!
Pokémon Super Mystery Dungeon: Team Charm is also present in Super Mystery Dungeon. In this game, Gardevoir has a connection to Gengar, hinting that she may be the same Gardevoir that appeared in Red Rescue Team and Blue Rescue team.
Spoilers end here.
This Pokémon was unavailable prior to Generation III.
Gardevoir and Gallade are the only Pokémon capable of Mega Evolution that are in the same evolutionary family.
Gardevoir resembles a principal dancer. Its exaggerated head with minimal facial expression and an overall frail, featureless physique could also be attributed to anesama ningyou, a style of traditional Japanese paper doll. Its loyalty and protective nature over its Trainer may suggest that it is based on a guardian angel or familiar spirit, though its ghost-like characteristics could also suggest that it is based on ghosts that refuse to leave the physical world.
Gardevoir may be a combination of garde (French for guard) and devoir (French for duty). It may also be a combination of garder (French verb for to keep) and voir (French verb for to see), reflected in its Pokédex data, which explains how Gardevoir will protect its Trainer even at the cost of its own life and that Gardevoir has the ability to see into the future.
Sirnight may be taken to mean さあ、ナイト saa, naito ("come, knight") or Sir Knight.