How many ways can a villain build a presence in a book, when he's trying to hold back and observe the MCs to learn their magic's secrets? My goal is to write the first half of the book with the MCs ignorant of how dangerous the villain is-- and keep the reader in the same boat, using only the MC's viewpoint. In fact, I tried to write those chapters with the villain completely hidden, showing only the people he'd sent against the MCs to test them, until I realized I didn't have enough interest in those thugs to carry those chapters alone. The options I'm looking at now are: He might put more pressure on the MCs in ways that start to hint there's someone behind the scenes, such as giving more hints to the enemy he's sent against them or making sure the MCs' friends are caught in the middle. At the same time he might save the MCs if it looks like they'll die before they figure out the magic, and/or give them hints that he can help them, maybe even asking them to prove themselves with the magic first-- that would be clearer that he's out there and focus more on how trustworthy he might be. And of course, the MCs might get a glimpse of him, or the other people who've dealt with their magic might suspect there's someone after the secret. Thoughts?