One spell to rule them all

[Bockscar]

Except it isn't. With a 6.30 sec cast time and being easily resistable, it's not that hard to protect yourself against it. Coupled with the insane 400 mana cost, most wizards can only cast three of them. There's even a +35 CR cloak in Kedge, or a much easier +20 one in Everfrost. It's the easiest resist to raise.