When an opponent's monster that was Tribute Summoned declares an attack: Destroy as many face-up Attack Position monsters they control as possible, and if you do, inflict 1000 damage to your opponent.
Rulings
Individual Card FAQs
When your opponent attacks with a monster that you Tribute Summoned, and your opponent took control of, you can activate "Blast Held by a Tribute".
Monsters like "Tyrant Dragon" cannot negate the effect of "Blast Held by a Tribute".
In order to inflict 1000 points of damage to your opponent, you must destroy all monsters on your opponent's side of the field first. So if you activate "Blast Held by a Tribute", and your opponent chains "Ring of Destruction" or "Interdimensional Matter Transporter" so that your opponent has no monsters to destroy, then "Blast Held by a Tribute" inflicts no damage.
Netrep Rulings
If all face-up Attack position monsters are removed from the field before "Blast Held by a Tribute" resolves, the entire effect of "Blast Held by a Tribute" disappears.
If a monster that has been Tribute Summoned attacks, it may be destroyed by the effect of "Blast Held by a Tribute," regardless of how long ago the monster was summoned. If a monster has been Special Summoned, it may not trigger "Blast Held by a Tribute," even if the monster has 5 or more stars.
Trap|
Normal