Very few games make crossovers, and unless you'd consider Kingdom Hearts a gaming crossover, you rarely see other game characters interacting with each other. Those wacky people at Capcom, known for mixing it up with other companies, have pitched in together with Atlus to form a rather interesting alliance. The main man (or is that devil man?) behind the Devil May Cry series, Dante, is taking his first brave steps into the world of RPGs. In Shin Megami Tensei III: Nocturne (Maniacs), Dante's role in the game is still a mystery, but it appears he has a connection with the story's main character in a "vortex world." The apparent motivation behind's Dante's appearance is due to the boy being targetted by the Devil, in addition to a bizarre attachment to a stolen treasure called "Menora." Nocturne Maniacs is a somewhat remixed version of Atlus' orginal title, and while information is scarce, more news will likely develop.
As of right now, Atlus' forum for the game is the best place to voice your opinions and concerns regarding Nocturne Maniacs. The thread in particular can be found here.