I read this great book when I was in my teens (20 years ago). It was out of print then. I don't remember the name of the book or the author, and relatively few details. I'm hoping someone here can take my woefully inadequate recollection and help me find this book. What I remember most clearly about the novel is the magic. The protagonist was locked away, I believe both physically and mentally, for a long time. The tale was very dark, with much suffering. It was this suffering that eventually made the character snap. The closest parellel I can think of is Robin Hobb's assassin's apprentice mental magic - the adverse conditions he went through training with the coterie has a similar feel to it. But unlike Hobb's magic, where it was a gradual strengthening, the magic in my forgotten tale was unleashed all at once. Best parellel I can think of here is Mercedes Lackey's Vanyel - the scene near the end of the trilogy where the dark mage traps him inside his own mind, and with the help of a 3rd rate healer he cracks the mental barrier and unleashes terrible rage. I know that isn't much to go on. This is kind of a hail marry request. But if that sounds vaguely familiar to anyone I'd really appreciate names/authors for fantasy books that were out of print 20 years ago containing these themes.