To obtain a Gallade in Pokemon GO, players must capture the previous Gallade evolution. The game’s Gallade is a Fighting-type and Psychic-type Pokemon, one of several to have evolved from previously introduced Pokemon. In Pokemon Go, the Ralts and Kirlia are the two evolutions of Gallade.
Gallade is one of the last forms of the Ralts, which can only evolve from the male Kirlia. Just as with the Pokemon games mainline, only male Kirlias can evolve to Gallade, meaning that you have to capture a male Ralts and evolve them to a Kirlia first. In order to evolve your Kirlia into Gallade, the Kirlia needs to be a male Pokemon, and you will need to use a Daybreak Stone on the Kirlia in order to evolve it to Gallade.
Gallade is one of the few Pokemon to have gender locking that is, to evolve into Gallade, a Kirlia must have a certain gender. Once you get a male Kirlia, the next step is to give it another Hundred Candy and Sinnoh Stone, and it will evolve into a Gallade.
To evolve a male Kirlia into Gallade, you need 100 Candies from the Red Pill and a Sinnoh Stone. In total, you will need 25 Ralts Candy to evolve into Kirlia, and an additional 100 Candy to evolve into Gallade. You will also need a Sinnoh Stone as an additional currency to evolve into Gallade.
Making the Male Ralts a Gallade requires an additional item in addition to the 100 candies; players will also need the Rare Sinnoh Stone in order to do so. Kirlia can then be evolved into a Gallade or a Gardevoir; in order to make Gardevoir, players will simply have to give their Ralts 100 Candy.
If the Ralts in the middle of the evolution are Male, and you use 100 Candy and the Sinnoh Stone, you will end up with Gallade, which is a fairly good offensive-type battler. You cannot catch a Gallade in the wild, but you can find a Ralts or a Kirlia in the wild that will evolve to a Gallade in the end.
Fortunately, in Pokemon Go, you have got a couple of choices when it comes to deciding what happens to your Ralts once they turn into Kirlias and evolve into Gallades or Gardevoirs. A Sinnoh Stone is usually good enough for the evolution of one of the fourth-generation Pokemon, but you need another to get your Gallade.