Embereth Skyblazer (ELD) from Throne of Eldraine, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Daarken
• Card Text:
  As long as it's your turn, Embereth Skyblazer has flying.
  Whenever Embereth Skyblazer attacks, you may pay 2R. If you do, creatures you control get +X/+0 until end of turn, where X is the number of opponents you have.