On my last gameplay the spell books named "Sparks" (find 2, if I remember) was for the skill "Elemental Hail"
(by the way a nice skill for killing more the one enemy at the same time and strong against Dragon Riders in the Wastelands, but it use many Mana!)
Deadly Discs is also great against enemies that have a waek/low armour ! Plus you can hit more than one enemy at the same time

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