On which mystic 4* should I focus on?

COLOSSAL_GAMER

I can dupe both of them. I've got 59 sig. stones. I just don't know who should I focus on.
I've never played with Scarlet Witch that much bug heard only good stuff about her.
2. I've played with Ghost Rider but again not that much. I know he doesn't need to be awakened but it makes him slightly better.

I would rank SW but don't know if it'll be better to use GR for the Blade synergy. Of course there's always option to wait.
Thanks in advance and Happy Holidays!