R4 Dupped 5* Domino or 5* Undupped CAIW

Trying to decide which would be better to r4?

My current team:
6* Corvus
5* Dr Voodoo (R4) dupped
5* Iceman (R4) undupped
5* Stark Spidey (R4) undupped
5* Spiderman classic (R4) undupped