Exactly. Note that there is a scientific study that indicates this appears to be the case with trolls in Internet commenting systems. So it's not exactly a big leap of faith to expect that PvP adherents, displaying similar aggressive behaviour for the "fun" of being aggressive and controlling, have similar tendencies. The big question, as the AC above indicates, is whether trolling, PvP, and violent video games act as an outlet for those urges and help control them or whether they feed and exacerbate them.
A decade ago, I had fun playing Quake III Arena death matches with other members of the development team, and I'm anti-sadistic, not at all Machiavellian, and pretty average when it comes to psychopathic behaviour. It was pretty easy to discern between the game and real life and treat it as an entertaining sport. So I think that even with the more realistic graphics in contemporary games, it's quite possible for normal people to make that distinction. The real question is whether psychopaths would prefer not to make that distinction, pretend the game is real, and in doing so aggravate their condition?
Mass and serial killers often have a history of serious animal abuse, which later escalates into even more serious human-oriented behaviour. So while enjoying bullying through virtualized violence in video games likely isn't a sufficient condition for the escalation of psychopathic behaviour to physical violence, it may prove to be a useful warning sign or even a catalyst in conjunction with other factors. Another significant factor for instance maybe whether the community of enthusiasts tends to and reinforces a distancing, demeaning, psychopathic attitude towards other players and "newbs", or maintains a more sportive approach. The recent Isla Vista shooting by the former PUA and PUAhate adherent Elliot Rodger seems to indicate this is a good candidate for a co-factor.