Whose next..?

THUNDERBIL

I recently got a GR and a Voodoo as 4 stars and both are unawakened. I still haven't managed to get blade but I do have a duped stark spider.
I have enough resources to take one of them to R5. So who should it be.

Fhfjghhggggjfhfjg

Ghost rider is ur best bet since dr voodoo is undupped