So currently there are no dungeons available for Hera-Is. I mean if you can beat Alt. Ultimate Arena-No Continue, then there’s a chance she’ll drop. But that dungeon is extremely hard, even for me.
However there are 2 easy ways to get her in the future.
1) Wait for Hera-is descended or Zeus Mercury descended. (It’s super easy to beat)
2) Get to Rank 110, so you can start trading with me. That’s how everyone helps each other get materials. I use it pretty often!