Ah, that's right. You were sleeping in that ice prison at the time. You likely never saw it.

[He looks up at the gorgeous dragon flitting through the clouds. It looks like it's having a grand time doing so.]

Back when your Hyrule became part of Reverein, I found it while looking for you. It was blue and very cold. Though at first it looked much darker and was covered in that Malice substance. It was trying to protect you, I think, but you were at risk of being crushed in its coils.

I have to admit that it was quite a fun fight.