I can rank up 2 to r4 at this point. Who do you recommend I rank up or should I wait for another 4* (I'm about 50 shards away from a 4* crystal)



I also have a 4*R4 Drax(duped), 4*R4 abomination (duped), 4*R4 X23(unduped), 4*R4 Ultron(unduped) and my only 5*R2 is Drax(unduped).
Any input on this decision would be helpful.
Thanks