There are a lot of new Pokemon to catch in Pokemon Scarlet and Violet, but there's a good amount of returning Pokemon as well. For example, players will recognize the familiar form of Gastly, the franchise's first ever Ghost-type Pokemon. Catching a Gastly is great, but players will no doubt be itching to evolve it into its two subsequent forms, Haunter and Gengar. Veterans will be pleased to know that the methods for attaining these evolutions has not changed since the original release of Pokemon Red and Blue, but it may still cause some confusion for newer players.
Gastly's first evolution sees it turn into Haunter, and this is achieved simply by leveling the Pokemon up enough. Unlike its first evolution, Pokemon Scarlet and Violet players that want to evolve their Haunter into a Gengar to finish the Gastly evolution line will have to delve into the game's trading system.
How To Evolve Gastly
Getting Gastly to evolve into Haunter is fairly straightforward. All players need to do is level up their Gastly until it reaches level 25. Assuming the Pokemon is not holding an Everstone that stops evolution, it will evolve into a Haunter automatically once it hits level 25. This is also when the Pokemon will learn the Shadow Punch move, a useful Ghost-type attack that can never miss. In order for the player's Gastly to reach its full potential, they'll need to evolve it one more time, however.
How to Evolve Haunter into Gengar
In order for Haunter to evolve into Gengar, the player must trade their Haunter away to another trainer. This may seem counterintuitive to new players, but it's always an option to simply have that player trade the newly evolved Gengar right back. On the bright side, this means that players can get Gengar immediately after their Gastly evolves into a Haunter at level 25. On the other hand, this evolution requirement has always been notoriously difficult for those players that primarily play through the game solo. There is currently no way to evolve Haunter into a Gengar in Pokemon Scarlet and Violet other than trading.
Gengar is a formidable Pokemon and has been since its inception. Its impressive speed and high Special Attack stat make it both a dangerous foe and a powerful ally, as the Pokemon is capable of sweeping the enemy team with powerful Ghost-type moves like Shadow Ball. Its Poison typing, despite giving it some nasty weaknesses, also mean it is effective with moves such as Sludge Bomb as well.
Pokemon Scarlet and Violet are available now on Switch.