For me, MG is a terrible character. He's boring, self-righteous and rude.
Some examples:
-he doesn't do anything and always whining
-when he blame Landon for his fathers believes
-when he said to Wade that "Just because I read comics books doesn't mean I have no dignity at all." He was jerk to him and he basically told him that he had no dignity but letter have a nerve behave as victim to Jed: "Jed, that's not my job to make you feel better about being a jerk." His behavior was as awfull as Jed and even worse because he hadn't had remorse and never apologize Wade.
-when Hope saved him when he was beaten by Rafael but he hide ascendent wich could save Landon (I understand his motives but if everyone know that ascendent wasn't destroyed they can create another solution.)
-He only help to by a hero not to doing something good, even Lizzie helps more selfless. She wanted to protect her little classmate Pedro and entire school even if she hurts in the process.
-when he go after something "popular": pretty witch Lizzie Saltzman or popular among vampire students Kaleb. He always have to be friends with people who are being consider special. (maybe this is exaggerated but I started thinking about it when he easy dumped Ethan and he started partnerships hero something with Kaleb, btw Kaleb was awsome but MG was again feeling to help only to feel "special" and hero.