Well I've been playing for about a year and a half now and I really have no idea of what I could play to keep me motivated. I've never really liked hard rock that much so I would get kind of bored with it. I would say that my technique is pretty good and I do have good knowledge of theory. But whenever I learn a lesson like Pavel's alternate picking halfway through and can play it at 60 bpm cleanly I just get bored of it. What are some slower but not necessarily simplistic metal riffs a guitarist like me should try to learn?