Shadow is an unusual monster.

It's a ghost type that has much higher Atk than Matk. It's like how Funkis, despite being a normal type and having skills that boost Atk, has higher Matk than Atk. And it seems that Shadow's Atk isn't too bad, lvl 28 it has 85 Atk.

Maybe they plan on introducing Psychic and Ghost Physical skills later.
Oh and Magical Normal skills.

or you can teach shadow like rampage, or kamikaze

I believe kamikaze is advanced skill, not 100% sure though...

Kami is advanced, so shadow couldn't learn it. But it would be great if they introduced physical ghost and psychic moves imo. Hopefully shadow is a sign of that like lexoph said.