The Terastal Festival ex subset largely contains reprints of various notable Pokémon and Trainer cards released in 2023 and 2024, including reprints of Pokémon ex and ACE SPEC cards. This set also debuts Eevee and the Eeveelutions as Tera Pokémon ex, and introduces a new Mirror Holofoil Poké Ball pattern that can appear on certain cards. Like in the Pokémon Card 151 subset, the Mirror Holofoil Poké Ball pattern has a chance to be a Master Ball pattern instead. Like other special subsets such as Pokémon Card 151 and VSTAR Universe, Terastal Festival ex booster packs have a chance of having multiple secret rare cards; such packs are colloquially referred to as "god packs". One particular type of god pack from Terastal Festival ex contains all nine special illustration rare prints of Eevee and the Eeveelutions, and one non-Holofoil card. Each Japanese Terastal Festival ex Booster Box contains 10 booster packs containing 10 random cards each.