Mystogan

Mist Gun (ミスト・ガン Misuto Gan) is one of the S-Class mages of the Fairy Tail guild.

Background
Mist Gun is a reclusive member of the guild, and as a result, his past is a mystery. Luxus has stated that he know what Mist Gun looks like and what he true name is, which is "Another-". However, Luxus was cut off by Mist Gun before he could finish.

Garuna Island Arc
His first appearance was at the beginning of the the arc, where he put all of the guild members to sleep, before he took a mission and left, leaving the guild quite mysteriously.

Phantom Lord Arc
Later, during the fight against the Phantom Lord guild, Mist Gun is shown to have gathered Makarov's lost magic together, giving the guild master strength to go to the battle site and defeat Jose Pola. When Polyushko questions why he didn't help the guild in their battle, he reveals a ton of Phantom Lord flags, which shows that Mist Gun had single handedly destroyed Phantom Lord's sub-divisions.

Fighting Festival Arc
His latest appearance occurs during the massive battle Luxus Dreher had staged between Fairy Tail members, where he calmly walks into the town, making the number of Fairy Tail members capable of fighting a total of four; himself, Natsu Dragonil, Erza Scarlet and Gazille Reitfox.

After the Luxus's minions defeat, Mist Gun confronts Laxus asking him to stop using the Hall of Thunder spell. He then gets into an argument about who is the strongest member of Fairy Tail, him or Luxus; Mist Gun says he doesn't care about such things though. Mist Gun get angry when he hears that Laxus knows something about him and he gets angry. With this, he tells Laxus he's about to see magic he's never seen before in their fight.

Magic & Abilities
Not much is known about what his magic revolves around, though as a S-Class mage, he is one of the stronger mages of the guild he seemingly used a sleeping spell to knock out all of the Fairy Tail members (save for Makarov) once when he was going to take a mission from the guild.

He apparently uses staffs in his magic since he has several during his latest appearance.

According to him, he uses magic never seen before.