What should I do with these domains?

I want to build a site for an adult niche so I found a couple of expired domains for that niche. Neither had amazing link metrics but it was better than starting from nothing so I bought both. One is an EMD with a hyphen and the keywords in reverse - that is, if the keyword was "blue widgets" the domain would be "widgets-blue.com". The other is a PMD. I thought of redirecting one domain to the other to improve the metrics. I'm intending on using them for a money site, not PBNs or anything like that.

The only thing is, the EMD was apparently in French, and all the backlinks are from French language sites, although they are all highly relevent. If I build a site on it, and redirect the other to it (which again has highly relevent backlinks and in English) will Google eventually send me the English language traffic I'm after? Will doing what I'm planning work anyway? (Leaving aside that there's no money in adult, I already know that). Is there an alternative arrangement I should consider?

Working on such a competitive niche as adult implies that even the best looking strategy has a big chance to fail, and it is logical to have 10-100 websites in this niche aiming on 10% success rate... But your plan to build a website on a French PMD domain and to redirect an English PMD domain sounds good (supposing that your domain has some general TLD rather than french one). Especially taking into account that fact that both of them have relevant backlinks (unless they are spammy). If the website succeed, it should certainly get relevant English traffic.

EMD PMD, what does that mean?

Exact Match Domain, Partial Match Domain. One is an exact match for the main keyword for the niche I'm using it for, the other has the keyword plus another word.