He is another one of the S-classed mages who puts everyone to sleep every time he comes to the guild mainly because he hates to be seen. Makarov is the only person who is left unaffected by his magic but it still makes him tired. Laxus states that he has seen his face as well. Mystogan carries a mysterious staff that has not been expanded upon yet. He has a bandit type mask covering the bottom half of his face and a cap covering the top with only a slit being shown between his eyes.
In chapter 120, when Mystogan attempts to stop Laxus and the hall of thunder, Laxus’ lightning attack causes Mystogan’s mask to burn off revealing a face that resembles Jellal’s. However, he denies that he is Jellal although he admits that he knew him.
Mystogan is actually the Edolas version of Jellal, and the renegade prince of Edolas.
In chapter 189, it was revealed that Mystogan was saved as a baby by Pantherlilly which caused his exile from Extalia.
Later on in chapter 268, Jellal took over the role of Mystogan and joins Fairy Tail. It is yet unknown how long he would stay with them.