I'm not seeing a guide about them. But how do you unlock the 5th star? I've got solids all his stars but he isn't 70 yet, I got sutera, I think that's her name...wood bow girl, too but she doesn't have all stars filled or lvl cap yet.
On a side note is the best place for medals only weekend dungeon and multiplayer battles?
Max their levels first, then a fate episode will appear that you can do in order to unlock the fifth star option. After that you have to limit break the last star, usually high requirements.
Not sure if any of the mods still support this community, but they should be aware that the forums are infested with bots and that their forum needs to be upgraded.