I already asked this but I didn't register so here we go again. I can’t remember much, as I saw it when I was younger (around 2006). But this boy acquires "the devil's horns" and it gives him powers. Also when he flies he leaves like gold dust particles in the air. I'm pretty sure he went to a school too and it was a crow in the school's yard that told him about his horns. Any help?
This sounds like Blue Exorcist, in that:
- The protagonist learns he's the son of Satan and gains horns (as well as fangs and a tail)
- The protagonist gains powers
- The protagonist goes to school
- There is a crow character, Gufu
He doesn't leave gold dust particles in the air when he flies, but he does leave blue energy trails in the air.
However, the series came out in 2011, which doesn't quite fit your timeline. Are you sure it wasn't a little later?