This one definitely suits Shintaro because

YO, he totally is a freaking legend. 

First of all, he's literally the only Light that can defeat THE DARK LORD once. (Though you all aren't sure exactly how he did it and when he did it. MWAHAHAHAH) He's freaking boss with his spells and magic and fighting skills, and like the song says, 

They never give in 

He never gives in, either! (Except once in Escape, but he knows that was a mistake.) 

They never lose hope 

He is always telling his friends (especially Kai) these things, because he knows if you give up hope, you're screwed. You have no chance. 

They run into smoke when the fire is fierce

I can so see Shintaro doing this. He would so run into a raging fire to protect what he knows, who he loves. It would so be something he would do. 

The scars collected all their lives

Yo, you guys have no idea how many scars I draw Shintaro with.

IT'S ALL BECAUSE OF HIS WONDERFUL LEGENDNESS AND HIS FATHER-

When everything's lost they pick up their hearts and avenge defeat

We literally see Shintaro do this in Found (Book 3). He swears to himself that he won't lose everything again, and he avenges defeat against his father, this time forever. 

And legends never die,

So his legacy will be carried on!