Hm...I don't really know. I figured they'd both be on the run. Witches are hunting Meisters/Weapons that side with Shibusen. Mitsui saved Sera. Then there's the madness creatures that are just roaming about. I was also thinking that they possibly run into a lesser witch that tries to fight them, or one of the witches pets. Basically solidifies the fact that Mitsui can't really rely on being part of the witches' sect.