Okay, I will go through small details first.
-There is not enough on description. If this guy was in a room of young, tan, black-haired males there would be no way to easily pick him out.
-Why does EVERY character have to obligatorily meet Crisis? Just a personal irritant. There's lots of other nice people out there to meet.
-Some random guy sacrifices himself just to save him? +1 Mary Sue point for you.
-Turns down a reward from a cosmic dragon just so he can screw around on a death world? I'm not sure if I should award a Mary Sue point here or diagnose him with severe Boy Scout Syndrome.
-Wait, his school will divert half the time of its students to help some random kid go to a world where he will die? Either he is very popular at his school, in which case you would deserve another Mary Sue point, or that school has got some serious management issues. Or he's sleeping with the headmaster. That tends to get you what you want at educational institutions.
-Woah, woah, woah, he has a SHIP now? One that can
traverse dimensions?! I think that needs explaining. And no, I don't think his school mates could have whipped it together for him in shop class.
-I'll assume he landed near a beach, or the sailing crew makes no sense. Best to clarify that.
-Okay, there is no reason to give him amnesia. That is just arbitrary and cliché. You get like... maybe... 12 Mary Sue points for that.
-Um, I think Vivian lives behind the Chordoni falls, or that's where she keeps her stuff. Even if she doesn't she will figure out someone is living there and your character and his friends will have a significantly shortened lifespan. And she
surely would have noticed all the people bringing in all the stuff for a base.
-And wait, high tech? Where the heck did he get high tech stuff?
-A group of people just going around with some random kid to save some dragon they don't know and, of course, helping random people? Remember, there is no disease on Felarya, so Boy Scout Syndrome shouldn't be able to affect the people here.
-Shadow Mage is interesting, or at least acceptable. But the link with his girlfriend giving him powers as their relationship develops that gives no explanation for how such a mental link occours? And the fire magic there for seemingly no reason? Try to streamline his abilities.
-Okay, so his school gave him all this technology? Like the dimensional ship? So its a school for Magic and Technological prodigies? My school was lucky if they could produce a basketball team that didn't suck, but his school is developing highly advanced technology and just giving it to some random student who just goes off with it? If my school built a dimensional ship they'd be looking for a damn grant from the government. Anyways, the equipment is cliché but alright I suppose. Still, a magic sword is not a practical idea. Yeah, try killing a naga with a magic sword. If you've read the manga, you will know just how horrendously bad an idea that is. And how can the hoverboard operate with "just a thought?" Does he have a relationship with it too?
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Okay, now the bio as a whole.
The big glaring problem with this bio is that about half of it just talks about his toys and magical powers. Another good chunk tells his story. There are a few shreds on appearance and nothing on personality at all. This seriously weakens the biography as a whole and you should really spend a lot of time developing the personality aspect. Equipment isn't really that important at all.
And, as I said, it seems that you just gave him a bunch of random, unconnected abilities. Try to develop a more cohesive character - maybe develop his shadow talent more, or his psionic, or his fire - but all three just thrown together is sort of random.
Though there is little personality, this character does set my Mary Sue alarms ringing. A super powerful, respected and loved character can easily get boring. Even the greatest heroes are complex people. Try to make him like a real person, not an ideal.