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>retards confuse natural teracrystal formation (raids) and natural (wild) tera pokemon with the trainer's usage of the phenomenon
Trainers terastallize their pokemon by using a Tera Orb, which contains a source of Terastal energy (Terapagos's shell). The Terarium Core core on the other hand, allows the existence of natural teracrystals and wild tera pokemon.
Natural crytals and wild teras only appear in Kitakami, the Terrarium and Paldea. The Tera Orb is an independent tool that can be taken anywhere.