Tezzeret the Schemer (AER) from Aether Revolt, available at 401 Games Canada.

• Rarity: Mythic Rare
• Finish: Normal
• Artist: Ryan Alexander Lee
• Card Text:
  [+1]: Create a colorless artifact token named Etherium Cell with "T, Sacrifice this artifact: Add one mana of any color to your mana pool."
  [-2]: Target creature gets +X/-X until end of turn, where X is the number of artifacts you control.
  [-7]: You get an emblem with "At the beginning of combat on your turn, target artifact you control becomes an artifact creature with base power and toughness 5/5."