She is a high-ranked succubus with the title "Love Tempest". Succubi feed of Qi from other people, and most of them need physical contact with their victims to do so. However, Kiskill Lira can derive Qi from others without physical contact. As long as her victims fall for her, she can use magics of Charm and distant manipulation to let her victims "give up their life forces voluntarily".
Her most powerful weapon is her "singing voice". Her singing voice is so sweet that a single phrase of her song can seduce her targets. According to records, she had once assembled many of her fans at a meeting place in Dark Zone, then slaughtered all of them by devouring every bit of their life forces.
Making one willing to give away their own lives... it sounds horrible, but that is one form of love in succubi's term.