Cerastes down, who should I take from nexus?

For some context, I’m 2/3 R4s from hitting paragon and I just pulled a 3-4 tech gem and I’m also sitting on 2 skill gems (thinking of using it on my NF and Valk). My current mutant roster consists of 5* Ascended AA, Mags, Colossus, and Domino. Need your help in this one y’all, thanks 



2
Comments
Ultron is good
Aegon needs dupe and high sig to carry more combo.