It was made under Altus and Capcom agreement (Capcom consulted Altus production team and that version of Dante was allowed by them), and Dante didn't demonstrate anything more there than he shows in DMC games powerwise. That game is just the ultimate show of which was stated in the end of DMC and DMC 2- than Dante has way surpassed his father's potential (his high demonic form in DMC 2 (Sparda form) was shortliving due to balance purposes but powerful enough to kill almost any enemy with a single energy blast) and becomes the strongest demon of his universe. DMC 2 is at about the same time as Nocturne and if you remember, Dante heads to Hell dimension to "clean" it. Nocturne explains how exactly that happens (though the RPG itself rather boring, we get to see Dante closer at its second half and main character is the f*cking emo Dante clearly outshines).
Nocturne Dante has even the same office and same weaponry set as DMC 2 one. And this isn't joke one like Viewtiful Joe version.
But Dante will never have on-panel confirmed planet-busting powers (comets, asterionds- that's allowable, but make him planet buster and he loses all his charm, since fighting skills based game about planet buster ends up being sh*t or comic relief like DBZ or Darkstalkers).