Blaze Cannon (Ultra Rare)

(This card is also always treated as a Blaze Accelerator card.)
One The Winged Dragon of Ra you control gains the following effects until the end of this turn. This card's activation and effect cannot be negated.
* This card is unaffected by your opponent's card effects.
* When an attack is declared involving this card: You can Tribute any number of other monsters that did not declare an attack this turn; this card gains ATK equal to the Tributed monsters' combined original ATK, until the end of this turn.
* After damage calculation, if this card attacked: You can send all monsters your opponent controls to the GY.