XYZ-Dragon Cannon

[ Machine / Fusion / Effect ] "X-Head Cannon" + "Y-Dragon Head" + "Z-Metal Tank" Must first be Special Summoned (from your Extra Deck) by banishing the above cards you control. Cannot be Special Summoned from the GY. You can discard 1 card, then target 1 card your opponent controls; destroy that target. ATK/ 2800 DEF/ 2600