The more I look at Reya the more I’m convinced that’s just Ava in the future. They look THE SAME. She’s just like a slightly older Ava. That would give Ava such a GOOD storyline for season(s) 3,4,5,6… IMAGINE.
After Ava put the crown on herself and she talked to Reya, she came back “knowing” she had to sacrifice herself. What if what she came back “knowing” was actually that she somehow had to die/cross over to the other side? Because she had some kind of important mission in some other dimension/realm? Think about it, one second she was asking Bea to take the Halo and let her die, but as soon as Lilith suggested crossing over the Arc she didn’t even put up an argument. She didn’t want to die, she didn’t want to stay alive but she wanted to “cross over”, whatever that means, the only thing she wanted was to fulfill her next step. Reya probably told her she has something or someone she will really care about on the other side.
What if she finally allowed herself to kiss Bea because “I’m the god you’ve been worshipping this whole time, anyway”?
She told her to live her life because she knew she wasn’t coming back, she had a mission, a responsability somewhere else.
How Reya looks at her past self in tears? How she’s moved by the memory of her first and only real love? Maybe at this point Reya/Ava has been missing Bea for centuries. I would cry for that.