Should I rank up any of my other 4*s?

Will3808

I’m posting this to ask if any of my 4*s that I don’t have at rank 4 or 5 are worth ranking up. I’m currently exploring act 4 so I’ve been playing a lot and was wondering if anyone else is worth ranking up. I have 4 5*s too so this isn’t my whole roster but only one of them is worth using.

Etjama

Ghulk, Medusa, Emma and maybe Mags when he gets buffed.