Hero's Blade (CMR) from Commander Legends, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Aaron Miller
• Card Text:
  Equipped creature gets +3/+2.
  Whenever a legendary creature enters the battlefield under your control, you may attach Hero's Blade to it.
  Equip 4 (4: Attach to target creature you control. Equip only as a sorcery.)