When this card is Special Summoned from your Graveyard by the effect of a Zombie-Type monster: You can target 1 Spell/Trap Card your opponent controls; destroy that target. During the End Phase of the turn this card was Special Summoned: Destroy it.
By using these cards, you can Special Summon Bone Crusher from your Graveyard and use its effect. Il Blud can special Special Summon 1 Zombie-Type monster from your Graveyard once per turn. This lets you to repeatedly Special Summon Bone Crusher and use its effect every turn. While Vampire Genesis has a similar effect to it, but it needs to discard Zombie-Type monster from your hand with a higher level than Bone Crusher to Special Summon it.
Destroys your opponent's Spell Cards / Destroys your opponent's Trap Cards / Destroys itself