Ghostblade Eidolon (C15) from Commander 2015, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Ryan Yee
• Card Text:
  Bestow 5W (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
  Double strike (This creature deals both first-strike and regular combat damage.)
  Enchanted creature gets +1/+1 and has double strike.