Tengu format ruling
Card Blocker
Card effect (current official text)When this card is Summoned: Change it to Defense Position. When a face-up monster you control is targeted for an attack: You can change the target to this card. When this card is targeted for an attack: You can choose a number from 1 to 3, then send that many cards from the top of your Deck to the Graveyard; this card gains 500 DEF for each card sent, until the End Phase.
Rulings
- The effect to increase the DEF of "Card Blocker" can be activated when the attack target is changed by "Card Blocker’s" own effect. The effect to change the attack target does not target. If you have multiple copies of "Card Blocker" on the field, you can only activate 1 of their effects to change the attack target when your opponent’s monster attacks. Sending up to 3 cards to the GY is a cost.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.