Unfortunately, as Ren figured, he tried but could not learn from the Demonology book. Still he decided to put it into his inventory now, hanging onto it for later. Having demons as summons to shield him would be very helpful. Plus knowing warlock magic also sounded interesting, accepting that as his second book of choice. 

When Lucian used the Observe Skill on the book the following text would appear in a window. 

[hider=Window]
Rituals for Communing with Nature for Morons
Base Item: Book
Rank: Somewhat Special

A Skill Book that teaches the Talent Skill, Basic Nature Power Rituals, which will allow the user to perform various rituals of power to commune with the forces of nature. 
[/hider]

It was unclear what Talent Skill meant at first, but with a little thought...

---
Lucian Int: 83 - 21 Int = 62
---

It took you a bit longer than it should have, but an idea came to you. A Talent Skill could be what unlocks a new Talent, a Skill that gives you access to a new Talent. It was only a thought though. Still, it was something useful to think about, in that this book could give you access to not just a new Skill, but instead a whole new Talent. 

As Saito heard Lucian talk about what happened he nodded, a small smirk appearing on his face after a few moments, but it only lasted for a moment before his expression grew a bit more serious. "It seems that I have discovered your power's one weakness. Most Natural Abilities start off strong or already useful, but not yours. It has unlimited potential for growth it seems if you can just learn anything without limits on how much you can learn, but time is required. Time to grind to level up, as I assume you can do that from what Ren here told me, time to learn new Skills that are out of your reach, and other such things. Essentially time is your weakness since you have unlimited potential, but not enough time to employ everything, and like game characters you could mess up and end up wasting alot of time..."

Ren's eyes widened as Saito said this. He had never thought of that before. Indeed even if their power could let them do so much there was only so much time in the day to grind or test and learn new Skills. Even shopping for weapons, grinding for new ingredients, or other such things would take time and who knew how much longer until the Hunters or whoever was after them attacked..."Yea... alot of effort and time..." Ren said in response to Lucian's last statement about putting effort into these things.