Mag Mell is a metamorphic sigil that allows Suzune to transform various body parts into that of a beast. She has been shown to transform her arms, such as creating bear arms, and used a horn on her head to sense where her opponent was. Using the sigil gives her immense speed and power, and for an unknown reason, her obtaining the sigil cured her heart problem. It is shown that Suzune suffers recoil depending on what she transforms her body parts into, becoming unable to move after creating and attacking with bear arms, though she had already been using her sigil to fight the Greed D so it is unknown what her actual limit is. She was unable to properly control her sigil at first, resulting in beast ears and a tail showing, but later becomes able to manage it.
After the timeskip, Suzune has become much more skilled at using her sigil, easily dealing with a group of Greed that attempted to attack her. She is more assertive and confident in her abilities as well, asking Danjou to allow her to head back on her own since she could be of help the most. She is also able to see in the dark, though it is unknown if it is due to her sigil.
- Mag Mell is a mythical realm from Irish mythology.