Terastalization

Terastalization, or the Terastal Phenomenon, is a temporary effect that allows a Pokémon to change its Type. When near a Tera Crystal, when carrying enough Tera Shards, utilizing a Tera Orb, or otherwise having a large amount of Typed Terastal Energy around, you may be able to surround yourself with said Terastal energy and Terastalize.

Effects

When a Pokémon is Terastalized, they are covered in a crystalline film. This does not impede their movement. Additionally, a large crystalline structure grows from the Pokémon’s head, which differs depending on which Type they Terastalized into. This structure is known as a Tera Jewel.

When a Pokémon Terastalizes, their usual typing is completely replaced. This means that a Tyrunt (Rock/Dragon type) which Terastalizes into a Fighting type will take super-effective damage from Flying, Psychic, and Fairy, and resist Rock, Bug and Dark, as any mono-Fighting type would.

There is one exception to the above: Stellar Type. For unknown reasons, a Stellar Terastalization retains the original Pokémon’s typing. For example, a Pawniard (Steel/Dark) will remain Steel/Dark, taking ultra-effective damage from Fighting, super-effective from Ground and Fire, and resist Normal, Flying, Rock, Ghost, Steel, Grass, Ice, Dragon and Dark, and be wholly immune to Poison and Psychic.

Regardless of which type the Pokémon Terastalizes into, they will be weak to Stellar-type attacks.

If a Terastalized Pokémon knows the move Tera Blast, the move will be the same type as their Tera type.

While Terastalized, moves of your types before Terastalizing and your Tera type are stronger than moves that don’t match your typing. This includes being typeless (such as a Fire type using Burn Up), gaining a type through Forest’s Curse or Trick-or-Treat, or having your type replaced (such as through Soak, Camouflage, Conversion…). If your Tera type matches one of your types before you Terastalized, moves of the same type will be even stronger.

The Ability Adaptability affects only moves matching your Tera type. Moves of a Power below 60 will have their strength increased to 60. Technician does not boost these further. Multi-hit moves, priority moves, and moves with variable power do not gain this boost, but moves that increase in power under certain conditions will have their power boosted to 60 if they would have less power when used.

Terastalized Pokémon cannot have their type changed from moves or Abilities; a Pokémon using Transform before Terastalizing will keep its own innate Tera type, rather than copy the target’s Tera type.

Additional notes

Certain foods may increase a Pokémon’s Tera Factor, which makes it easier for them to Terastalize. Additionally, it is possible to change one’s Tera type through particular food recipes, which may involve Tera Shards as ingredients.