Bituminous Blast with no target.

Bituminous Blast can not be cast unless there is a valid target. But, what happens when there is a valid target at the time Bit Blast is announced and that target somehow becomes illegal before Bit Blast resolves?

This circumstance could happen many ways. For example the target creature leaving the battlefield or receiving protection. Before resolving, Bit Blast checks it's original target and if it is no longer legal Bit Blast is countered (fizzles).

However, Cascade is a triggered ability. As soon as Bit Blast is moved onto the stack the Cascade ability is also added to the stack, directly above the Bit Blast. Therefore, the Cascade ability resolves even if Bit Blast is countered.

Quote :

702.82. Cascade

702.82a Cascade is a triggered ability that functions only while the spell with cascade is on the stack. “Cascade” means “When you cast this spell, exile cards from the top of your library until you exile a nonland card whose converted mana cost is less than this spell’s converted mana cost. You may cast that card without paying its mana cost. Then put all cards exiled from the game this way that weren’t cast on the bottom of your library in a random order.”

702.82b If a spell has multiple instances of cascade, each triggers separately.

I was wrong before, Warren, sorry about that.

Sam was wrong?!