Gold and lack thereof ...
I am currently broke. I had millions a while back when I hit this bottleneck. Now I'm at a different stage. I'm sitting on 3,4,5 star crystals I can't open, I'll have no space for the iso and no gold to level even if I got a character I like. As it is I'll just grind arena anyways and use tickets to slowly fund my teams.
I have only 2 5* stars any good at 3/5 45/45. How the heck am I ever gonna level these up with no t4's and only 7k gold. And 6 stars coming out soon.... wth....