Ep 18. Ark

After being blackmailed, the brothers meet with a man convinced humanity is heading towards it's end. On their way out the three who ambushed them before show up to kill them. But they aren't too much of a threat because Naoto's power has become much stronger. He's able to block all of their attacks without any wasted effort. Shouko shows up, but only to say goodbye because hse isn't able to keep her form any more. After returning to the other world they find Futami's message. It's a list of people found by the Ark, including those who were eliminated by them.