Tough rank decision
5* Ultron (0 signature) from 2/35 to r3
4* AoUV (42 signature) from 4/40 to r5
Similar Ultron champs are:
Doctor Voodoo (limited sustain)
Wolverine/X23 (regen)
Similar AoUV champs are:
4* Hawkeye (control)
5* Hawkeye (control)
Dormammu (control)
Magik (control)
Gwenpool (control)
Doctor Voodoo (control)