This guide details how to obtain and utilize Hydreigon, a powerful Dark/Dragon-type Pokémon in Pokémon Scarlet and Violet. Hydreigon's evolution line (Deino and Zweilous) is exclusive to Pokémon Scarlet, requiring trading or transferring to obtain it in Pokémon Violet.
Obtaining Deino:
Deino and its evolution, Zweilous, can be found in several locations within Pokémon Scarlet: Alfornada Cavern, Dalizapa Passage, Glaseado Mountain, Area Zero, and North Province (Area Two). Higher-level Deino (levels 35-40) reside in Alfornada Cavern and Dalizapa Passage, requiring Koraidon's high jump ability to access the former. Three-star Tera Raids also offer Deino encounters, potentially with its Hidden Ability. Zweilous appears in four-star Tera Raids. Hydreigon is found in five and six-star Tera Raids.

Transferring Deino to Pokémon Violet:
Since Deino is Scarlet-exclusive, players of Violet must utilize trading via the Union Circle (requires Nintendo Switch Online) or Pokémon HOME. Pokémon HOME allows transferring from Pokémon Sword/Shield, Pokémon GO, and Pokémon Scarlet. The process involves moving Deino to the Basic Box in HOME, then transferring it to a PC Box in Pokémon Violet.

Evolving Deino:
Deino evolves into Zweilous at level 50, and Zweilous evolves into Hydreigon at level 64. Auto-battling or using Exp. Candies (especially L and XL) accelerates this process.
Hydreigon's Strengths and Weaknesses:

Hydreigon boasts a base stat total of 600, excelling in Special Attack and Attack, with respectable Speed. A Timid or Jolly Nature is recommended. Its Dark/Dragon typing provides advantages against Dragon, Ghost, and Psychic types, but it suffers a 4x weakness to Fairy, and also has weaknesses to Fighting, Bug, Dragon, and Ice types. It resists Grass, Water, Fire, Electric, Ghost, and Dark attacks, and is immune to Ground and Psychic. Terastallizing mitigates the Fairy weakness.
Stat |
Base Stat |
HP |
92 |
Attack |
105 |
Sp. Attack |
125 |
Defense |
90 |
Sp. Defense |
90 |
Speed |
98 |
Total |
600 |
Suggested moves include Nasty Plot, Dragon Pulse (or Draco Meteor), Dark Pulse, and Flash Cannon (Steel-type coverage via TM). Because of its vulnerability to Fairy, a Steel-type move is highly recommended.
Hydreigon's versatile movepool allows for both physical and special attack strategies, making it a formidable addition to any team.