Mutant rank up advice

Reference

Among those unduped 6* mutants, which one you would rank up first? Thanks.

De_Potato_Salad

Cable

Cable if you have a high level apoc, if not I’d do domino

Noobda

Cable

If you have apoc as a 5*/6*.

Reference

Thanks De_Potato and Noobda, I have 5*r5 Apoc.
How about Stryfe? Is he good as horseman as well? I seldom use him after pulling. Thanks.

Reference

Thanks for the votes, it seems to be a draw game now. I tend to pick Cable or Stryfe atm despite I know Sunspot / Domino are good champs even unduped. For OR, I reserved 50+ mutant sig stones and I hope to get him duped sooner or later.