[Single-Card Discussion] Number 23: Lancelot, Ghost Knight of the Underworld

2 Level 8 monsters
(This card is always treated as a "Laundsallyn" card.)
While this card has Xyz Material, it can attack your opponent directly. When this card inflicts battle damage to your opponent: You can target 1 face-up monster your opponent controls; destroy that target. Once per turn, during either player's turn, when a Spell/Trap Card or another monster effect is activated: Detach 1 Xyz Material from this card; negate the activation.