Renovation

Viable yes, but Mana Recovery's (Inspiration sounds stupid) boon is too great while being incredibly easy to acquire, and ranking it may or may not be difficult unlike Sakura Abyss. I have 1k MP and healing 500 mp every 3 minutes. Its pretty much an insult to Meditation, as well as the hard work you have to go through for getting Holy Eagle Mask (lots of RNG, economy, etc. etc.).

Why would I want to put in any effort for a silly Mask when this skill solves all my mana problems?

Because during those 3 mins, you need to keep your mp up somehow before Inspiration. Hell should I know. All I know is you can never have too much MP as a mage.