I was pretty sure Yda was going to be the the "Red Lady". Then it got confirmed. Then it turns out Yda wasn't Yda, so Yda wasn't the "Red Lady". What a twist.
I liked the story, but also think they should've introduced it along with the patch 3.55. Or even with the 3.5.
Also, regarding Shinryu
Maybe it's just that Domans just confused it with their legend and Eorzeans decided to use that name. But what if Ilberd actually casted an spitting image of the legends? That'd means that Ilberd knows about Doma in some way. Perhaps there's someone else plotting behind the scenes (could be an Ascian or could be someone else).