Soul Eater Not! Chapter #13
To produce this technique Crona and Ragnarok must perform a Scream Resonance after absorbing a large amount of human souls. The combined power of performing this Scream Resonance after the consumption of so many souls allows Ragnarok to take the form of a dragon extending from Crona's back, complete with two large wings.
In this form Crona's attacks are all enhanced, shown when he/she used Screech Alpha to destroy the Flying Dutchman's ship, Nidhogg, with just a single blow. He/she also gains flight capability, which is fast enough to give even Death the Kid a tough time keeping up on his Beelzebub. This form was only shown once though and has yet to appear again.
- Crona's "Black Dragon" ability appears to be based on Emine's ability to create wings to fly, which is likely constructed out of his own blood, from Atsushi's earlier series B. Ichi.