Nagi no Asukara

[Ryllharu]

I don't think Manaka will wake up simply because they took her from the sea god and brought her to the surface. That would be too easy. I suppose it does provide a different reason for the ED if she does. It's not that she woke up decades after the others, it's that she can't live underwater anymore.

I also think it was Manaka herself that was guiding Miuna around. Not just because she accidentally said her name when guided by the ena flakes, but because Manaka was her friend too and wanted to be reunited with the lot of them.

The only reason I can think of for her ena eroding is that she's a sacrifice to the sea god. She has to drown, like the original bride/sacrifice for it to count.

[Kraco]

The only reason I can think of for her ena eroding is that she's a sacrifice to the sea god. She has to drown, like the original bride/sacrifice for it to count.

And she took five years to drown for what reason? If that was the only reason why it's happening, it would have happened a long time ago. It can't be a coincidence Miuna gained her ena and Manaka is now drowning, at the same time. Though I don't really know why it's happening at all, aside from what I said: Uroko (Sea god) does whatever they want, following simple whims.

[Ryllharu]

It can't be a coincidence Miuna gained her ena and Manaka is now drowning, at the same time.

It can be a coincidence. The same noise Miuna is now attuned to is the same one we heard when Hikari woke up. It was also the same one we heard when Kaname woke up, which was coincidentally the same time Miuna gained her ena.