I know you said pokemon, but I just wanna throw pokemon out there again. Pokemon is really good.
1) If he doesn't have a wiiU Mario Kart is really good.
2) The 3ds Zelda is awesome, very much worth having.
3) Almost everyone I know who has a 3ds has Animal crossing, it's a really good game. However I donno if it's cool enough for a 13 year old. I know I probably wouldn't have played it when I was 13. Same goes for tomadachi life.
4) Theatrhythm, but only if he already likes final fantasy. That game wouldn't be nearly as fun if you didn't know the songs going in.
Other than that the games you mentioned make up a solid library
Ps. pair it with 6 -10 games?! That's insane, you're insane.... insanely awesome, but seriously seek help.