A Pokémon TCG: Scarlet & Violet—Obsidian Flames booster box contains 10 random cards per pack with 36 packs total, 1 Basic Energy per pack, and a chance for new Tera Pokémon ex cards, including powerful Charizard ex. This set introduces new Trainer cards and features over 20 brand-new Pokémon ex, with a total of 230 cards in the expansion. 
What's in a pack? 
10 cards: These are random cards from the expansion.
1 Basic Energy card: A fundamental card for playing the game.
What to expect in the Obsidian Flames set:
Tera Pokémon ex cards: 
The set features type-shifted Tera Pokémon ex, such as a Darkness-type Charizard ex, according to Midwest Cards. 
New Pokémon ex: 
Over 20 brand-new Pokémon ex cards are introduced in this expansion, according to GameStop and Midwest Cards. 
Trainer cards: 
The set includes more than 15 new Trainer cards, according to Midwest Cards. 
Silver borders: 
As part of the Scarlet & Violet series, Obsidian Flames cards feature silver borders. 
330+ cards in total: 
The entire Obsidian Flames expansion contains over 230 cards for collectors.