Majin Form, often referred to as "Desperate Devil Trigger" (or DDT) by fans, is Dante's true demon form. In this form, Dante becomes invincible and has immense power. Only usable if Devil Trigger is activated while Dante is in critical (red) health. In this form, Dante wields a pair of twin blades that protrude from Dante's forearms as his melee weapon. While in this form, Dante is able to fire enormous fireballs, as well as a lesser known, huge beam attack of which there are two variants, Dark and Light. This form can kill most bosses in a few hits, such is it's power.
A common misconception by fans concerning the Majin Form of Devil May Cry 2 is that Dante supposedly transforms into the Dark Knight, Sparda when he activates the Devil Trigger while in critical health. In retrospect, this is somewhat understandable, as Dante does become astoundingly more powerful, not to mention invincible, and that the Majin Form has some physical similarities to Sparda.