User blog comment:Rjwstar/MGQ world`s various untold informations - Torotoro blog Q&A(2)/@comment-24006918-20160129035033/@comment-26095998-20160129055723

Remember the fact that Luka is a child of the 2nd Seraph? Also, in paradox, it turns out that Luka have a super intelligence brain, so he can even  calculate 8965x964 just by mental arithmetic, and even factoring 129878627 within a second. Ilias explains that he also inherited his mother`s high intelligence, and if he have proper education, his intelligence will be much more greater. I think the sword skill is a same case.