His skill is among the top level in Fairy Tail; however, due to past events, he is no longer able to use Take Over to transform his entire body. It is revealed that in the past, an error occurred with his full-body transformation, leading him to lose control over his actions. Lisana, his younger sister and former member of Fairy Tail, sacrificed her life to break his concentration and help Elfman regain sanity. As a result, his most recent attempts at full-body Take Over induces a flashback of his sister, breaking his concentration and causing the spell to fade. This event has also caused Elfman's heart to lock shut.
During the attack on Fairy Guild by Phantom Lord, Mirajane is taken hostage while pretending to be Lucy. Elfman, determined to overcome this setback and keep his vow to "never see his sister's tears" helped him regain the ability of full-body Take Over, helping him defeat Sol, a member of the Elemental 4.
It seems both he and his sister Mirajane were badly hurt in the past due to their younger sister, Lisana, dying. It's said that Elfman's heart is locked shut because of what happened to Lisana. Mirajane is very concerned for Elfman when she found out he went with Gray to help out Natsu in the Phantom Lord guild building, though Kana feels that he will be fine.
Elfman is an enthusiastic character, seemingly obsessed with manliness and regularly spouting (sometimes nonsensical) speeches about manhood, and what it is to be and act like a man..