[Oh, he brought it up knowing she would ask more--]

Why, making a contract with a demon, of course! The desire for power is one of the simplest ways men fall to demons -- depending on the strength of the demon in question, even a person with no prior experience with magic can become quite powerful almost instantaneously.

Naturally, I receive many such benefits from my familiars! Not that I wasn't already rather skilled in magic beforehand, of course.