Annwn

Just chills.

He acknowledges the impossibility and then immediately decides he is going to ride into Anwyn alone anyway.

Because Gwydion understands the fundamental difference between a forecast and a duty, a prophecy may dictate the odds of success, but it does not relieve an individual of their moral obligation to try.

The impossibility of the task is entirely irrelevant to the necessity of the attempt.

It's a brilliant pivot.

Gwydion starts explaining to the group what he is actually riding into.

He has to explain what Anwyn, the death lord's domain really is because we usually picture the villain's lair as a torture chamber or like a throne room made of skull.

Spikes and lava everywhere.