Marcus from Blazing Sword is a gamebreaker in every sense of the word. High base stats allow him to trivialize the earlygame chapters, and his growths, although subpar, are just good enough to allow him to crush enemies all the way until the end of the game (even in Hector Hard Mode). Access to 3 weapon types gives Marcus a weapon for every situation, and high movement allows Marcus to quickly defeat chapters. The only point against Marcus being a gamebreaker is that he is reliant on gaining around 2-3 points of spd throughout the game at a 25% growth, something that he has a non-negligible chance at failing to do even if his average stats at a certain level indicate that he is expected to do so; regardless, he is still by far the best unit in the game even when failing to gain spd.