Let the Galaxy Burn

Cascade triggers when you cast the spell, meaning that it resolves before that spell. If you end up casting the exiled card, it will go on the stack above the spell with cascade.

A spell's mana value is determined only by its mana cost. Ignore any alternative costs, additional costs, cost increases, or cost reductions.

Two new cards in this set give the next spell you cast cascade. This means that the next spell you cast gains cascade as you begin to cast it by putting it on the stack, and the cascade ability will trigger when you finish casting that spell.

If a spell with cascade is countered, the cascade ability will still resolve normally.

When the cascade ability resolves, you must exile cards. The only optional part of the ability is whether or not you cast the last card exiled.