Personally, I think Tenzen will be the ultimate threat against both Oboro and Gennosuke and that they will have to team up in order to defeat him. Oboro is the only one who could actually prevent Tenzen from just getting up again with her dispelling gaze.

As for Saemon? He's smoked. There's not a fucking chance that he will survive against Tenzen. Did you see that smile on Tenzen's lips as he was toying with the confused Saemon? Now that's the stuff I love about this show.