Royal Assassin [Fourth Edition (Foreign Black Border)]Set: Fourth Edition (Foreign Black Border) Type: Creature Human Assassin Rarity: Rare Cost: {1}{B}{B} {T}: Destroy target tapped creature.

They win by building new buildings and crafts

Set: Base Set Unlimited Type: Colorless Rarity: Holo Rare Retreat cost: Colorless

put a -1/-1 counter on enchanted creature

" —Herman Melville

When Knowledge Vault leaves the battlefield

−3: Target creature gets +X/+X or -X/-X until end of turn

*Available only in certain regions

Set: Legends Type: Legendary Land Rarity: Uncommon {T}: Add {R}

-UG Boulder Deck Cases

Set: POP Series 9 Type: Water Rarity: Common Retreat cost: Colorless

as confirmed in correspondence with him here and here

For an extra challenge