Debtors' Knell

Flying Whenever a creature attacks you or a planeswalker you control, you may draw a card.

This creature can't be blocked. When this creature enters, you gain 4 life. When this creature enters, sacrifice it unless U was spent to cast it.

When this creature enters, detain up to two target creatures your opponents control. (Until your next turn, those creatures can't attack or block and their activated abilities can't be activated.)

Defender (This creature can't attack.) Flying When this creature blocks, sacrifice it at end of combat.

Vigilance When this creature enters, look at the top three cards of your library, then put one of them into your hand and the rest on the bottom of your library in any order. When this creature enters, sacrifice it unless W was spent to cast it.

Defender, flying

Flying Whenever this creature attacks, detain up to two target nonland permanents your opponents control. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Choose one — • Creatures you control gain lifelink until end of turn. • Draw a card. • Put target attacking or blocking creature on top of its owner's library.