
Don't be a hypocrite, your argument is "we were told this so it must be true". The series started with showing him swinging a sword, and reading books as training and that's literally it. His brother does the same sword swinging and the MC can only understand and memorize the contents of the books because he's mentally older.No offence, but maybe polish your arguments a little. His effort were both shown and told, yet your argument is "nothing really shows it"? The series literally started with MC desperately training and learning so his asshole 'father' would pay attention. It's a major part of his character. Oh well, I guess not everyone pays attention.
Then by your own definition, the MC is a cheat. He is the only person in this world's history to have Dark/Black Knight as a skill.Basically, if it offers power, effeciency, something that does not currently and would never exist in the world, and/or resources, but with no cost or effort from your part, it can be considered a "cheat ability".