Don't get it whether you want to work with casinos as an owner or just work for them as an affiliate manager or marketing person. I would suggest you to just join any casino and get in touch with them about special affiliate programs as most of the casinos are able to offer you special commissions if you can bring them enough traffic.

If you want to work as an owner of the casino or some kind of partnership then I don't think many options are there for you because all the known crypto casinos are well established and won't want to share their revenue directly.