Sebek explains that his unique magic Living Bolt (hidden meaning: Lightning Flash) “turns the caster into a bolt of lightning that can be used for maneuvers or offense.”
While we do not see Sebek’s unique magic until Book 7 he says that he learned it before he enrolled at NRC, born from his desire to get to Malleus’ side faster than anyone else in the event of an emergency.
Sebek says, “I’m still a long way from properly acquiring it…it remains so unrefined that it leaves me with harmful after-effects when I use it,” and he hadn’t intended to use it in front of others until he had completely mastered it.
Epel downplays his own unique magic when asked, saying that he can only hit with around 70% or 80% efficiency, and Sebek responds, “What!? You can cast it that reliably!?”
Sebek uses it for the first time on-screen in Book 7 in order to save Silver from the abyss, and though he says he is unable to use it afterwards without becoming deadweight he does use it a second time in order to save Silver and Lilia from Silver Owls.
The third time we see Sebek use his unique magic in the main story is again in Book 7, to break up a fight between Jade and Floyd. He uses it a second time in Book 7 in order to save Ace, Grim and the prefect from being captured by darkness.
Sebek uses his unique magic twice during the Nightmare Before Christmas event, both times on Skully.
Twisted Wonderland Reference Note 