Stylish Nero
We Dem Boys!!
DmCDante defeated 5 or 6 bosses while Virgil helped in one boss battle. if you're looking at who's better from there track record Dante still wins.
Well considering that Vergil wasn't a playable character that account sounds a bit redundant and one must assess how Dante defeated said boss and they're level of power or challenge.
Vergil may have only defeated one high ranking demon on his own (Beowulf) versus Dante who did in 6 demons (although one was an unborn infant and the other a floating head with an obvious weak spot as well as an immobile giant slug who wasn't made for fighting as well Mundus who was weakened and even had help from Vergil) where as with Beowulf was a fully grown demon who was at his full power is fully capable of movement and Vergil still finished him off in one clean slice in a second using only precision and blinding speed (who lets not forget gave Dante troubles in his fight against him).
Beowulf<<<<<<Bob, Spawn, Hunter, and Succubus
If Vergil can pwn those 4 the same way he pwned Beowulf.....and Dante.
He even finished off the Hell Vanguard in one clean blind strike.
He even defeated Dante before his power up meaning he could defeat any enemy Dante has fought prior to his fight (Cerberus and Agni and Rudra).