Mashup: the Gathering Workbench: Virtual Booster

This booster was generated with modern collation since the cardset contains mythics: 1 rare / mythic, 3 uncommons, 10 commons, 1 basic land.
You could alternatively have 15 random cards regardless of rarity.

Castigating Specter R Creature – Specter When Castigating Specter enters the battlefield, return a white or a black creature you control to its owner's hand. When Castigating Specter enters the battlefield, or deals combat damage to an oppoenent, look at all and exile a card from all player's hands. 3/3	Blade of Shiv U Artifact Blade of Shiv enters the battlefield tapped. Sacrifice Blade of Shiv, , : Counter target artifact spell. Sacrifice Blade of Shiv, , : Destroy target artifact. "Sturdy boots, a strong cloak and a stronger sword. If you want to thrive, though, you'll need something extra." -Shivan Guide	Roiling Fire U Sorcery When you cast Roiling Fire, exile it from the game with X time counters on it. At the beginning of your upkeep, if Roiling Fire is exiled, remove a time counter from it. If you do, deal 5 damage to target creature.	Abductive Discovery U Sorcery Choose one or both – Return target sorcery card from your graveyard to your hand; and/or return a card at random from your graveyard to your hand. "No one can predict when or where lightning will strike. I'm good at guessing, though."	Thanatos Drake C Creature – Drake Flying , , Exile a card from your graveyard: Target player discards a card. Activate this ability only any time you could cast a sorcery. 2/4
Pull of Pyromancy C Enchantment When Pull of Pyromancy enters the battlefield, put a 3/3 Red Elemental creature token onto the battlefield. At the beginning of each player's upkeep, Pull of Pyromancy deals 1 damage to that player, unless he or she controls an Elemental.	Harmonic Vale C Enchantment As Harmonic Vale enters the battlefield, choose a color. Whenever a player casts a spell of the chosen color, you may pay . If you do, you gain 2 life.	Corona of Power C Snow Snow Snow Enchantment – Aura Enchant green creature. Enchanted creature gains ": Deal damage to target player equal to this creature's power. I call on forest's strength – on every thorn on every bramble – for their mass to break our enemies. -from The Fire within All	Book Slide C Instant When you cast Book Slide, X cannot be more than the number of attacking and blocking creatures on the battlefield. Draw X cards. Each day, the Librarians of Lat-Nam fight against the growing tide of books. The books are winning.	Steaming Sink Pits C Enchantment – Aura Enchant Land Enchanted Land is a Swamp and Mountain. Whenever enchanted land becomes tapped, that land deals two damage to its controller.
Blessing Unbent C Instant As you cast this spell, you may untap two tapped white creatures. When you do, copy it and you may choose a new target for the copy. Target creature gains +2/+2 until end of turn.	Prismatic Surge C Instant As an additional cost to casting Prismatic Surge, discard a card. Target creature gets +X/+0 where X is equal to the discarded card's converted mana cost, and has protection from the colors of the discarded card.	Curio Curse C Enchantment – Aura Enchant Creature When enchanted creature deals damage to a player, look at the top three cards of your library, put one in your hand, put the rest back in any order, then sacrifice Curio Curse. Enchanted creature must attack if able.	Necrospawn Liege C Creature – Zombie Cleric Tap an untapped creature you control, or lose 1 life: Put a devotion counter on Necrospawn Liege. Remove five devotion counters from Necrospawn Liege: Draw a card. 3/3	Swamp B Basic Land – Swamp

Castigating Specter (rare)
Blade of Shiv (uncommon)
Roiling Fire (uncommon)
Abductive Discovery (uncommon)
Thanatos Drake (common)
Pull of Pyromancy (common)
Harmonic Vale (common)
Corona of Power (common)
Book Slide (common)
Steaming Sink Pits (common)
Blessing Unbent (common)
Prismatic Surge (common)
Curio Curse (common)
Necrospawn Liege (common)
Swamp (basic)