I use 2 schools of thought when blending hop varieties - balance a hop's characteristics with something very different, or accentuate the character with a similar, complimentary hop. So given its fruity and wild (neomexicanus) character, a balance of something like Chinook or Simcoe with the Medusa would give some nice piney, resiny notes and balance. But I think using another mid-AA, mid-oil hop like Azacca (peach/mango/light pine), Amarillo, Lemon Drop, Cascade, or Idaho 7 (which has a wild, fruity character of its own) could be nice, too. If you are specifically wanting to use the Columbus or Cascade with it, I'd use Cascade - It's a universal blending hop in American styles IMO.