Celestial Crusader (C14) from Commander 2014, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Jim Murray
• Card Text:
  Flash (You may cast this spell any time you could cast an instant.)
  Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
  Flying
  Other white creatures get +1/+1.