Overload

Strategy and Synergy
A spell that pretty much pays for itself thanks to the infinite mana regen, which basically allow you to spam ANY spell in the next three seconds. It's important to notice that, while powerful, this spell also isn't on use, unlike most calamity-tiered spells, allowing Overload to be cast multiple times in the same battle.

Due to its unique ability it can fit in any deck, provided you can first afford its massive mana cost of 6.

Trivia
When Overload was first added, it also applied root.