Please hide WN/LN/manga spoilers.
MAL entry, Anilist. The zeroth episode is a spin-off-ish, focusing on Sylphy after the Calamity meeting with Ariel, becoming “silent Fitz”, and struggling with her new situation; as well as the power struggles between Ariel and her brother I-always-forget-his-name for the Asuran throne.
It was a nice change of pace to have an episode where Rudeus was not the focus. This series has a bunch of interesting characters and great worldbuilding, so I hope we get some episodes that focus on the adventures of other characters this season. Either way it was a nice re-introduction to the world and story.