[Trigger] Stronger Spellbooks?

[CrueIIntentions]

I have ahero with 4 spellbooks. Each level gives him another spell in a certain area. What i need to know, is my spells i want to get stronger after a certain amount of uses, up to level 3 so basically i need the trigger to be after a certain amount of times cast, that certain spell gets stronger. How would i go about doing this?

NOTE: I have all the spells set as integers i dont know how to make the spell stronger individually. or disable spells.

 

[DarkLordX]

I would say you make if the unit uses the Spellbook set its Ability to next Level.