If they did blue mage they should do it like mundras, where each button is a different type of creature. Like one button could be bird which would give you helldive and a button for demon which would give you condemnation, but if you combine them you get eyes on me from an ahriman(bird+demon). Just my idea! I think learning blue magic like everyone wants them to add like they did in 11 in unrealistic for this game, and would cause to much drama and kicking. "You dont have xxx spell from this gated content? Then gtfo!" type of situations.