Please me & my fiancé have been together 6 years lving in UK and engaged. In those 6 years we never spent a day apart. Now 6 years later they have taken him back to Nigeria and we are planning on finding a way to be together. Anyone have any ideas? I am british citizen born and bred in UK, he is nigerian

Taken back(assumed deported). Within those 6 years, why did both of you not plan on an exit and re-entry strategy?
Did you have any legal framework in place prior to deportation or he just lived under the radar?
Unfortunately, you might have to visit him in Nigeria to get married @ a registry, provided you have all the supporting documents and earn enough to meet the criteria set, then time is the issue on or against you.
They might waste his time after application, but a spousal visa would eventually be iissued.
Patience is key !!!

You seem to opening threads(about the same issue), and not sure about what steps to take !!!!

If he was deported under violation of immigration and visa rules and allowances, then he has a penalty period to wait before he can be granted any merit for applying any return to there...
Explore the details of the penalty period and conditons if you are in those circumstances.. If you are serious, you can explore moving to Nigeria if within your means and then appealing to the Consulate there and better chance if he is actually your husband...
Or settle in Nigeria if the means for making it there is within your grasp..