Hmmm, let us see...
The first time Vergil is said to be honorable is in DMC1 by Dante, who likes V attitude without knowing who the guy is, but DMC1 novel shows V as being a total scum who is totally perverse, to the point of killing an defenseless old lady with a shotgun that belongs to her.
In DMC3 manga, Dante seems to think about V as having no honor saying " A man like you reduced to a demon's spawn! How sad!", so Dante does not hold V in high regard anymore.
The only thing people seem to associated with honor is the fact V doesn't like to use guns, but he used it anyway, even if it was once. A lot of thieves and murders do the same, they prefer physical confrontation over a cowardly approach...
Unless this character is badly written ( which he is), definitively he has no honor.He is prideful, but not honorable.Now, in the speculation field, if V will do what I think he will in DMC4 SE, any honor he could still have will go down the drain.
Am I wrong?