Zhulodok, Void Gorger

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.

You exile the cards face up. All players will be able to see them.

Once you announce that you're casting a spell, players can't take action until you've finished casting it. Causing Zhulodok, Void Gorger to leave the battlefield after you've cast a colorless spell from your hand with mana value 7 or greater won't stop that spell's cascade abilities from resolving.

If the card has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.

Each instance of cascade triggers and resolves separately. The spell you cast due to the first cascade ability will go on the stack on top of the second cascade ability. That spell will resolve before you exile cards for the second cascade ability.

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