Rank down Mordo for unduped Dormammu?

Now with a 5* rank down ticket, should I rank down 3/45 duped lv40 Mordo to rank up unduped Dormammu? Mordo is pretty useless offensively for me. Dormammu seem to have more utility offensively and much better defensively once awaken. I have MD5 if that matter.
What would you do?
What would you do?
1
Comments
i am looking to R5 my 4* Unduped one. he's a great champ.