You can Ritual Summon this card with "Contract with the Dark Master". Once per turn: You can roll a six-sided die, then destroy all monsters your opponent controls if you roll 1 or 2, destroy 1 monster your opponent controls if you roll 3, 4 or 5, or destroy all monsters you control if you roll 6.
1/3 chance to clear your opponent's monsters. 1/2 chance to destroy 1 monster they control.
Good attack stat.
1/6 chance to destroy all your monsters, usually resulting to your loss.
Costly to summon.
Zorc is a high-leveled Ritual monster making him costly to summon, but with proper support he could be worth the cost. Ritual Raven can be used as the entire cost for the summoning. Ritual Cage protects Zorc from being destroyed by card effects. Meaning he and other ritual monsters you control are also protected from his effect when you roll a 6.
Since Rolling a 6 is extremely bad, we want to avoid it at all costs. Dice Re-Roll allows you to roll the dice again to invalidate your first roll in case you got a 6. Since you can only use Dice-Reroll once per turn, only use it when you roll a 6. If you are brave enough you can try to re-roll and get a 1 or 2 if ever you get 3, 4, or 5.
If ever you get a 6 and end up destroying Zorc, you can activate A Deal with Dark Ruler to special summon Berzerk Dragon from your deck. Berzerk Dragon has a huge 3500 attack and can attack all your opponent's monsters, but has no inherent protection making him vulnerable to effects so you should be careful.