Obsidian Flames in the Pokémon TCG will bring in a new concept called type-shifted Tera Pokémon ex.

This means that certain Tera Pokémon ex cards will have a different Energy type than their usual type. For instance, Charizard ex, which is normally a Fire type, will appear as a Darkness type in this expansion. Similarly, Tyranitar ex, which is typically a Fighting or Darkness type, will be seen as a Lightning type instead.