(Cliché, I know, but wait. Just wait.)
Luke, Selina, Charles, Bianca and Zoe were recruited to Chaos' army. While they are all powerful, they are nothing compared to Aklios. Aklios is Chaos' personal assassin, whom they've never met. All they know is that one, he's the second most powerful being in the universe, only bested by Chaos, two, he bests Chaos at assassination, and three, he's slightly insane. Oh, and Slightly means So insane he can't conduct a normal conversation easily.