This attack is very similar in structure to Screech Alpha, as it also assumes the form of a mouth, but it is instead connected to Ragnarok's weapon form movements. The attack itself follows either an upwards or downwards slash, taking the form of a large mouth that follows the arc of the preceeding sword swing, vastly increasing the range of effect of the slash. The attack is dark black with a purple aura and outline. This was used by Crona against Maka Albarn in their first fight.
In the anime, while utilizing the Black Dragon resonance Crona uses this attack against Death the Kid and its appearance differs, appearing like a massive afterburner that pushes Kid backwards and creates a strong purple flare towering above the Ghost Ship Nidhogg. It appears to also be pushing Crona upwards, as they're sent spinning in a spiral.