My first 5* Rank 5?

Ctuchik

So i am going after Christimas and New year eve for my first rank 5 since someone new and great could show up. And I cant really decided who i want.
Ive got a decent variety of 5* roster at rank 3.
Im focusing on beating Ultron of act 5 and later on exploration. I havent touched any of the variants.
Between work, family, arena, AQ, aw and eq. I am pretty slow player advancing the story and permanent content.

Octoberstack

Can’t go wrong with Fury, CMM or Domino tbh. CMM at r5 will melt through most Act 5 content, and though she’s not the best for the final Ultron (due to her frequent armour breaks), you can guarantee that she’ll deal a hefty amount of damage before going down.

Regardless of who you decide to rank, I’d recommend having a crack at V2 - between your R4 Venom and Domino w/ trinity you should be able to make your way through a first time clear relatively easily