Pokemon Scarlet and Violet's Paldea region introduced the terastallization phenomenon. Using this power, trainers can change the type of their Pocket Monster and give them a substantial boost to attacks of the same elemental type.
When it comes to changing certain Pokemon into Water Tera Types, there are a few different reasons trainers may do so. Some use Water-type terastallization to give their Pocket Monster a boost to their Water-type moves. Meanwhile, others use it to protect a given creature from elemental weaknesses like Fire, Ice, or Steel-type moves.
Both are viable options, but some Pokemon in Scarlet and Violet benefit more from being terastallized into a Water-type combatant.
Note: This article is subjective and reflects the opinions of the writer
Azumarill and other top Pokemon to terastallize into a Water-Type in Scarlet and Violet
Dondozo surprised more than a few trainers when it began to carve out a high place for itself in the battle meta, but it isn't hard to see why. It has high HP, defense, and attack stats that make it a behemoth to take down.
Dondozo may be slow, but it hits like a truck. Trainers who want to give this Pokemon even more damage output can terastallize it into a Water-type to double the damage of moves like Liquidation, Aqua Tail, or Wave Crash.
2) Wash Rotom
Featuring exceptionally high defense, special attack, and special defense stats, Wash Rotom is an Electric/Water-type Pokemon that can deal some heavy damage and shrug off special attacks. However, it can still be exploited by Ground-type opponents and moves, which is one of its few weaknesses.
By terastallizing Wash Rotom into a pure Water-type, it loses its weakness to Ground-type moves and gains a huge damage boost to moves like Hydro Pump.
Azumarill's durability is well-known among Pokemon trainers in Scarlet and Violet, but its offensive potential could use some help. This is exactly why terastallizing it into a pure Water-type is so effective. It makes the creature bulky and capable of hitting pretty hard with Liquidation and Aqua Jet, among other moves.
Furthermore, transitioning Azumarill into a mono Water-type with terastallization protects it from Poison-type moves and Pokemon, as it loses the Fairy typing that makes it weak to poisonous arsenals.
It's no secret that Quaquaval benefits from terastallizing into a pure Water-type for various reasons. It removes three of its elemental weaknesses (Flying, Psychic, and Fairy-type) while also powering up hard-hitting attacks like Hydro Cannon, Liquidation, Surf, and Wave Crash.
Considering Quaquaval already has a remarkably high base attack stat, doubling the damage of its physical Water-type moves is a no-brainer. It simply makes Paldea's Water-type starter an even more potent offensive force in any battle arena it finds itself in.
Gyarados has been a powerful offensive force since the earliest days of the Pokemon franchise, and the advent of terastallization has only made it more dangerous.
Terastallizing Gyarados into a Water-type removes its weakness to Rock-type moves and opponents while enhancing the damage of its Water-type attacks. Since Gyarados has such a high attack stat, doubling the damage of physical Water-type moves like Waterfall and Aqua Tail will do it a huge favor.
Trainers should just be careful around Electric-type foes, as Gyarados still has a weakness to that type after terastallizing.