Saw the videos
This book is real aggro. I was just fidling with one of my own spellbooks: "wow i has nothing that can stop this guy/girl"
Armor and especially defences seems to be a possible counter..
Guards with interception might be a problem to.
I like that you have multiple of the important spells.
I like that you have build a really good spellbook, that forces people to think twice before they cast a lot of mana/action generators.
A few spells id might change/add:
Hurl Rock for something similar but unavoidable (block/reverse attack)
Id like a Posion Blood or something like that, maybe a few other curses as well.
An Enchanters Wardstone might be nice.