Mighty Chesnaught has the Rock Tera Type, and will have the same mark, Ability, and moves as in its original appearance in Black Crystal Tera Raid Battles between May 12th to May 14th. Black Crystal Tera Raid Battles contain much stronger Pokémon than those appearing in ordinary Tera Raid Battles, and give out better rewards. In the overworld, the Black Tera Crystals associated with these raids can be differentiated from other Tera Raid crystals by their aura and black sheen, both of which are also clearly visible when looking at crystals on the map. This Chesnaught can only be caught once per save data, and players who caught it during the initial run will not be able to catch it again during this re-run. Chesnaught cannot normally be encountered in Paldea, but may appear again in other events or be encounterable in different ways in the future.
To encounter these Pokémon in Tera Raid Battles, players will need to download the latest Poké Portal News. If players have connected their Nintendo Switch system to the internet while playing Pokémon Scarlet or Violet, this will happen automatically. Players can also manually download the Poké Portal News by selecting Poké Portal from the X menu, and then selecting Mystery Gift, and then Check Poké Portal News. After that, players will be able to start a Tera Raid Battle with Great Tusk or Iron Treads simply by walking up to and interacting with an appropriate Tera Crystal in-game. For Mighty Chesnaught, players will need to have completed certain postgame events in order to start the Black Crystal Tera Raid in this manner. Players who haven't yet completed these required postgame events can still participate in these Black Tera Raid Battles, but only by joining with other Trainers in multiplayer, such as by using a Link Code.
A paid Nintendo Switch Online membership is required to participate in Tera Raid Battles with other Trainers online, however players will still be able to challenge these Tera Raid Battles solo (supported by AI), or with other Trainers in local play without a membership.