Don't leave until you've clarified your equity stake and dotted all your Is and crossed all of your Ts. However, you should then cut your losses and get out of there. Half of a job is with whom you work and you've learned a great lesson with 'idiot' detection. I've worked with assholes recently, and they can actually be amazing assets at a company, but about 10 years ago I stopped working with idiots and I haven't looked back.
I'm starting a cloud company in Nairobi if you want to do something totally crazy ....