Pokemon Scarlet and Violet's Terastallization is a Double-Edged Sword for Team Composition

gamerant.com:

As is customary with every new set of mainline Pokemon games since Generation 6, Pokemon Scarlet and Violet have their own region-exclusive battle gimmick: the Terastal phenomenon. Terastallization was revealed in Pokemon Scarlet and Violet's third trailer, and it's an interesting mechanic in that it allows players to change the types of a Pokemon to its Tera type, which can be any of the existing 18 types in the games. This tool will be extremely versatile in many Gen 9 battles, as players have control over how and when to use it for both offensive and defensive means.

Because Terastallizide Pokemon can become either a completely new type or use the Terastal phenomenon to empower one of its existing types, this can be used as a strategic means to make some bits of the games easier, or as a tool to change one's team composition. It's possible that Pokemon Scarlet and Violet's Terastallization will have problematic use cases due to the way the games are designed, yet it can be both good or bad for the team-building process in Gen 9, which means that players should pay close attention to the way Terastallization functions.

Predicting Pokemon Scarlet and Violet's Remaining Tera Type Symbols

Pokemon Scarlet and Violet's Paldea region will be seemingly completely free to explore, with no restrictions on where to go first and what sort of Gym to undertake, which is a revolutionary approach for the series. However, it also means that Gen 9 will be much harder to balance in terms of battles, as Gym Leaders need to have teams that can scale up or down depending on the players' level. So far, Gym battles have been a staple of the series to challenge trainers by using specially trained teams of Pokemon who share one main type for each