I have a question, Reed and MC went to the same school, correct? I think that there was even mention of both of them sitting at the same desk, so they would have to be the same age, but Reed is early 20s and MC doesn't have a set age and can be anywhere between 20 and 30, so I don't understand how does that work, wouldn't that be a plothole?
No it wouldn't. The Academy doesn't work like a normal school and children learning to master their afflictions have joined classes (some of them) regardless of their age. It all depends on how old they were when their gift has awakened and their tier. At any rate feel free to browse through my Tumblr (#lore tag is what I think you might be interested in) as I have already answered a lot of interesting questions here.