Level up choices?

[Zhuangzi]

There is a great spell for regenerating Mana - I think it is called Magic Spring or something like that. At level 3 it gives +5 mana every time the stack is hit, plus a 30% defensive bonus, for 3 turns. This is a great way to get some mana back later in a long fight. Give it to your stack of Griffins and plonk them down in the middle of a pack of weak spiders or something.