Pact of Negation [Masters 25] Kaladesh Inventions and has "Whenever a player

and has "Whenever a player casts a spell or a creature attacks

You may cast a spell with mana value less than X from among them without paying its mana cost

where X is the mana value of a commander you own on the battlefield or in the command zone

Legendary creatures you control enter the battlefield with an additional +1/+1 counter on them

Set: Secret Lair Drop Series Type: Legendary Creature — Dragon Rarity: Mythic Cost: {5}{G}{G} Flying

Pact of Negation [Masters 25] Kaladesh Inventions and has "Whenever a playerSet: Masters 25 Type: Instant Rarity: Rare Cost: {0} Counter target spell. At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game. Those who expect betrayal at every turn are seldom disappointed.