Absolute skills

Can you explain how to obtain ultimate abilities?

I would also like to know this. I don't fully understand what we're talking about. All I did was download the skill tree and now I'm trying to level up my heroes based on it. For example, I want the Wizard to get Omniscience, and here are the paths to it: Fundamentals of Sorcery - Secret Knowledge - Counterspell - Shifting Magic - Omniscience... or: Magic Mirror - Shifting Magic - Omniscience...