I just layed out a simple track for him (1 take)
And i let him scream into the mic.

He likes Bodom, Killswitch, As I Lay Dying, Pantera, Tallica, etc.

7 Year Old Brothers Metal Link

The other track " Future Song " is what i want him to record over next.
I'm not a big hardcore fan, but he sounds easily as good as all the other hardcore singers I've heard. Props to your little brother.

I listened to future song, as well.... Even if your brother is going to sing something over that, the intro shouldn't be so repetive. I think it might be better if you played the main repeated line in the intro either 2 or 3 times.

If 3 times, place a slightly modified version of that, or heavily modified version, with the same rhythm for the 4th repeat.

If 2 times, you should probably just descend down the scale progressively with the 3rd and 4th rep. The note I'd bring down progressively is the highest note you play in that riff.

But that's just me, and I know that was unsolicited. You can leave it at 4, but once you get past that, it becomes very repetive. I don't recommend past 4.
There was some Sad But True in that.
Your brother made me laugh, he reminded me of that little kid who was walking in the street and started head banging just because I was wearing a Kill 'Em All t-shirt.
I'm sure you're brother had a lot of fun, didn't he?
it starts with fun and games, but at that age, you can really learn some good and bad habits. What im getting to is, if hes good at it, keep it up. It would be pretty odd to find a 12 year old singer who can out scream someone vocally in some large venue (think big).

heres my piece, if you can shoot a criq. http://mthree.zdsquared.com/Files/Embossed.mp3