Wasnt there a thread about a week ago about a "new manga coming out" and the main char was Aeys and he looked remarkably like your "concept"
Btw, I'm sorry to be blunt but I'm sure every single battle anime fan has come much further than this while thinking about random manga stuff, if this is what you have after years of envisioning a manga it's very, very little, but that's not the biggest problem, that is art, that concept couldn't pass a manga, if after years that is the concept that's a problem ... It's way too simple and basic, maybe it would make a better impression if you drew him facing many different ways, it's a lot different to draw the characters facing forward or at different angles, even the forward facing caharacter doesn't look good but that's by faaaaar the easiest, it's much, much harder to draw him moving ... For example just drawing him with his hands in a different pose would be much tougher, and after that you get different facial expressions, moving limbs, different angles, backgrounds, ...
How goes it with all the character's backstories/personalities/relations/..., the general big plotline of the manga and the world-building?
Sorry but being nice about something that lacked quality never forced anyone to come far