If that happens to my evil Nord who basically will have the "Weak people who don′t stay out of my way and those that fight dishonestly deserve death" policy then he will most likely join, only to find time with every single member, alone, in a closed room, far from any witnesses.
But the first thing of all he will do is find the strongest armor and shield he can find, honest and strong steel that allows for no trixy (spelled incorrectly on purpose) fighting.