Do not question demon powers. Their coats turned into wings when in devil trigger.
But I'm sure in that case he changed them himself at some point in time.
Slightly on topic, those who say that Vergil cannot be that one talking to Dante because "they can't work together" or "will fight each other at sight" is just stuck in the DMC3 storyline too much. Yes, it's a reboot, but even if it wasn't I still could see Dante and Vergil working together beforehand. In DMC1 you can clearly hear an old memory of Dante when he was with his mother and Vergil and they were playing happily like brothers.
At some point, Vergil became all evil-ish and started to want power. And think about this, what would be the reason for Vergil wanting power in the first place? It could simply be to become stronger than Sparda or something pretty straight forward. But they said Nero was Vergil's son, meaning he had him sometime before DMC3, so maybe his reason to get power had something to do with it?
LOL I could make a whole game out of Vergil's story before DMC3 and how he got there by making him fall in love with someone and having a kid.
So if in the reboot Vergil and Dante are working together then maybe when they were smaller they were good friends and then something happened that set them apart.