This guide details how to obtain and utilize the powerful Dark/Dragon-type Pokémon Hydreigon in Pokémon Scarlet and Violet. Hydreigon, a pseudo-legendary Pokémon, boasts impressive stats and is a valuable asset to any team. However, its evolutionary line (Deino and Zweilous) is exclusive to Pokémon Scarlet.

Acquiring Deino:

Deino can be found in several locations within Pokémon Scarlet: Alfornada Cavern, Dalizapa Passage, Glaseado Mountain, Area Zero, and North Province (Area Two). The easiest to access are Glaseado Mountain, Area Zero, and North Province (Area Two). Those in Dalizapa Passage and Alfornada Cavern are higher-leveled (35-40). Koraidon's high jump ability is necessary for Alfornada Cavern.

Deino also appears in 3-star Tera Raids (unlocked after 3 Gym Badges), offering a chance for a different Tera Type and its Hidden Ability. Zweilous, Deino's evolution, can be found in 4-star Tera Raids and in the same wild locations as Deino. Hydreigon itself can be obtained from 5/6-star Tera Raids.

Transferring Deino to Pokémon Violet:

Since Deino is Scarlet-exclusive, trading or transferring is required for Pokémon Violet players. The Nintendo Switch Online membership is needed for Union Circle trading. Alternatively, Pokémon HOME allows transfers from Pokémon Sword/Shield, Pokémon GO, and Pokémon Scarlet.

1. Move Deino to your Basic Box in Pokémon HOME. Save and exit.
2. Open Pokémon Violet in HOME and transfer Deino from the Basic Box to a PC Box. Save and exit.

Evolving Deino:

Deino evolves into Zweilous at level 50, and Zweilous evolves into Hydreigon at level 64. Utilize auto-battling or Exp. Candies (L and XL recommended) to expedite the leveling process.

Hydreigon's Strengths and Weaknesses:

Hydreigon possesses a 600 base stat total, excelling in Special Attack and Attack with good Speed. A Timid (+Spd, -Attk) or Jolly (+Spd, -Sp.Attk) Nature is recommended.

Type Effectiveness:

• Super Effective Against: Dragon, Ghost, Psychic
• Weaknesses: Fairy (4x), Fighting, Bug, Dragon, Ice
• Resistances: Grass, Water, Fire, Electric, Ghost, Dark
• Immunities: Ground, Psychic

Terastallizing mitigates Hydreigon's 4x weakness to Fairy-type moves. Offensively, consider changing its Tera Type for STAB (Same-Type Attack Bonus) on powerful moves. Its moveset allows for both physical and special attacking strategies. Flash Cannon (via TM) is a crucial Steel-type move to counter its Fairy weakness. Other suggested moves include Nasty Plot, Dragon Pulse (or Draco Meteor), and Dark Pulse.