This is one of my favorite two chord progressions. Minor, then to the minor a major third down (E minor - C minor). I wore this out for many years as the darkness of it is just right for me. I've incorporated it into many original pieces.
You have two quite different scales to work with but a hybrid scale(s) can be made. For example, I superimpose a C diminished7 chord over the C minor chord and get closer to the E minor (with F# now added). Then I can use this scale C,D,Eb,F#,G,A,B and can play this over both chords. The C diminished7 built into that also acts as as V7-9 resolving nicely to the E minor. This is just one of many examples of scale variations and combinations that can be used here. I think this fits with what I was using in the piece today.
You have two quite different scales to work with but a hybrid scale(s) can be made. For example, I superimpose a C diminished7 chord over the C minor chord and get closer to the E minor (with F# now added). Then I can use this scale C,D,Eb,F#,G,A,B and can play this over both chords. The C diminished7 built into that also acts as as V7-9 resolving nicely to the E minor. This is just one of many examples of scale variations and combinations that can be used here. I think this fits with what I was using in the piece today.