Reddit reviews Bound to the Abyss

There's Bound to the Abyss by James R Vernon.
A boy discovers a forbidden tome on Abyss magic (summoning demons and such) and that he has the rare talent to use such magic. However, the tome is in the language of the Abyss. The book takes place years after he discovered the tome and so has some idea how the Abyss magic works but all he really has to go on are his own trial and errors and information from his imp friend that was the minion of one like him previously and thus knows some things. The three books so far are filled with his attempts and failures at growing his talent with Abyss magic.

Added Bound to the Abyss to list.