XZ-Tank Cannon

[ Machine / Fusion / Effect ] "X-Head Cannon" + "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 face-down Spell/Trap your opponent controls; destroy that target. ATK/ 2400 DEF/ 2100