Back in the day, I did a prequel anime pitch that centered on how vergil and dante fell out before DMC3 so a large portion of it took place in high school. They were raised by an uncle(Eva's younger brother, former cop) who hunt demons after they killed Eva's mom, his wife and half the whole town. They had a female cousin named Nanako who is about 9-10.
Dante is more class clown than douche bag and more easy going. He thinks of his uncle as more of a hero than his dad as his uncle stayed and keeps fighting despite the the enormous odds where he views his dad as a coward who ran away at the first sign of hardship. His favorite superheroes are Punisher and Ghost rider.
Vergil dresses sharply and acts stiff and polite. He is socially awkward and tends to read a lot of old books like the divine comedy. He tends to be the more rebellious of the two and is fascinated by his demon half and otherworldly culture as a whole.There will be an arc where Vergil becomes an intern for the vassal of Amertarasu.