There were three main Viper players during 3.0, and they were (of course) Marlin Pie, Chrisis, and KBeast. Both Chrisis and KBeast played Viper/Dante/Magneto, and they are a testament to how absolutely ridiculous that team was. It's still very good, I'm sure, but I have a very strange feeling, seeing as Marlin Pie dropped Magneto and Ammy for Dante and Vergil. He had one of the best Magnetos out there, probably the best, but his main is Viper, and he builds his teams solely around her. So given that, there has to be a reason why he didn't continue playing Magneto; perhaps in the transition to Ultimate, his synergy with Viper and Dante decreased, I'm really not sure. Viper/Dante is still the best duo though, outside of Dante/Vergil (Hella synergy going on here, like most people wouldn't believe), so it's okay.