Can someone explain bound spells and power levels to me. I know you cast them with power dice during magic phase like a normal spell, and i understand the miscast part of it. what i wouldn't know how to do is deal with spells not already in the book, thus with no casting cost.

Particularly this has to do with the woodwaking wands spell. Its power level 12 (which i have no clue what that means). So what do minimum casting value do i need to reach? And what does power level mean?

Also another question...could you cast something like fireball (or superfireball cataclysm) on a wizard on a fulcrum...cause that seems an easy way to destroy wizards if you blow them up with 6d6 hits...