Karn, Scion of Urza (Promo Pack) [Dominaria Promos] Pegasus Set: Modern Horizons 2 Type:

Set: Modern Horizons 2 Type: Creature — Archon Rarity: Mythic Cost: {6}{B}{B} Flying

They only specify the consequences should you fail

Set: Diamond & Pearl: Majestic Dawn Type: Lightning Rarity: Holo Rare Retreat cost: Colorless

where X is that card's mana value

In ancient China

Karn, Scion of Urza (Promo Pack) [Dominaria Promos] Pegasus Set: Modern Horizons 2 Type:Set: Dominaria Promos Type: Legendary Planeswalker Karn Rarity: Mythic Cost: {4} +1: Reveal the top two cards of your library. An opponent chooses one of them. Put that card into your hand and exile the other with a silver counter on it. 1: Put a card you own with a silver counter on it from exile into your hand. 2: Create a 0 0 colorless Construct artifact creature token with "This creature gets +1 +1 for each artifact you control."