Ep 15. The The Rouran Dancing Whip that Dances in the Darkness

Fudou is extremely angry that Makubex sent Emishi in and forced him to postpone his fight with Ban. However, Makubex has another plan for Ban and Shido: Emishi will gain their confidence and then take them off guard. At this point Ban and Kazuki independently come to the realization that "IL" is really an "implosion lens": one of the ingredients of an atomic bomb that Makubex is building.