Karn, Legacy Reforged (Future Sight) [Mystery Booster 2] Hour of Devastation Prerelease Promos but with fire's power comes

but with fire's power comes its unpredictability

Set: Alpha Edition Type: Sorcery Rarity: Rare Cost: {2}{R} Each player discards their hand

Set: Tempest Type: Land Rarity: Uncommon {T}: Add {C}{C}

then attach this to it

Karn, Legacy Reforged (Future Sight) [Mystery Booster 2] Hour of Devastation Prerelease Promos but with fire's power comesSet: Mystery Booster 2 Type: Legendary Artifact Creature Golem Rarity: Mythic Cost: {5} Karn, Legacy Reforged's power and toughness are each equal to the greatest mana value among artifacts you control. At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.