Tengu format ruling
Mystical Knight of Jackal
Card effect (current official text)When this card destroys 1 monster on your opponent's side of the field and sends it to your opponent's Graveyard as a result of battle, you can then return the card to the top of your opponent's Deck.
Rulings
- In order to activate the effect of Mystical Knight of Jackal, the monster that Mystical Knight of Jackal destroyed as a result of battle must be your opponent’s own monster, not one of your monsters that your opponent controls.
- If Mystical Knight of Jackal attacks a face-down Man-Eater Bug, and Man-Eater Bug destroys Mystical Knight of Jackal, then the effect of Mystical Knight of Jackal is not applied.
- Mystical Knight of Jackal does activate its effect even if Necrovalley is in play.
- When Mystical Knight of Jackal attacks Mystic Tomato, during the End Step both effects activate simultaneously once Mystic Tomato is sent to the GY, so they form a chain. The turn player’s effect is Step 1 of a chain, and the opponent’s is Step 2; so Mystic Tomato resolves first, and a monster is Special Summoned and the Deck shuffled. Then the turn player chooses whether to place Mystic Tomato on top of the owner’s Deck with the effect of Mystical Knight of Jackal.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.