This episode was really jam-packed with content, and not all of it is obvious.
For instance, the Demon Child. As I had mentioned when the previous episode was released, I didn't see how the child could be featured in the memories in a way that made sense, and so I wasn't surprised by his absence. He was a great symbol for what went down during the Eclipse, but that didn't mean he would be in there. However, Miura didn't just draw him as a placeholder. I believe seeing the Demon Child in this context has brought Schierke and Farnese much closer to learning about Guts and Casca's son, who I think we all know will be central to much of the story going forward. It will fit with the other puzzle pieces they've gathered, like the Moonlight Boy's strange power and his affection for Casca (and Guts).
I also think what went down between Farnese and the Sprite has all but put an end to her crush on Guts. I had noted this earlier on in the dream sequence, and I think her resolve to help Casca get over her trauma further solidifies it. We will most likely get one last scene where she reflects on it, but it's pretty much done. On that topic, I find it amazing that Farnese and Schierke can have that much character development while this part of the story isn't about them specifically. It's the kind of dense but coherent storytelling you can only find in Berserk.
Obviously, the biggest development of them all occurs at the end, when Farnese draws from her own experience, from her personal journey, and resolves that she will help Casca through her trauma like Guts (and the others) helped her through hers. Very powerful memory (a bit reminiscent of Guts in volume 17), and it both establishes Farnese as Casca's soon-to-be confidante (a rearranging of group dynamics I had predicted years ago), but also as the group's future therapist of sorts. That might include helping Guts and Casca find each other again, but it could be more as well. Isidro, Serpico and Schierke all have issues they could use some help with...
The memories contained in the last fragment were what we expected: what broke Casca, meaning the Eclipse and more specifically her rape by Femto. It lasts only four pages, which is shorter than I had figured it would be. I feel that a full page of Femto looming over her and a bigger shot of Guts being pinned down would have better underlined the horror and despair of the situation. That being said I can see why Miura chose to focus on Casca's feelings, on her inner eye, and like I said earlier today I really like how he depicted the shattering of her mind. Schierke and Farnese's dialog also lends it much more weight, what with Schierke warning Farnese in advance and that incredible shot of Farnese's eyes as she experiences Casca's unspeakable pain.
The falcon's attack was also expected, and while I can't say it served a deep purpose, it was effective at adding the necessary tension to the scene. I really like how it is depicted in this episode, and I like that it has the upper hand on the dog, even with Farnese's little armor boost. The way it simply ceases to exist, along with the rest, as soon as the last fragment is inserted in the doll was what I wanted to see and I like how it was done. That, along with how the dog returns at the end, fully healed, and howls to complete the ritual, also validates what I posited when we were introduced to the nightmare. All elements were parts of Casca: the dog was her fighting-spirit, the part of her that struggled and didn't want to give up. The Sprite represented her true self, her ego. The broken doll was her broken mind, and the falcon and assorted monsters were her dark emotions, resulting from the Eclipse, the parts of her that prevented her to return. Those were dominant, which is why she couldn't regain herself without outside intervention.
Side note: Farnese still clearly refers to Guts when she tells the Sprite she'll soon meet the one she longs for. Time will tell who the Sprite actually referred to, but the fact it literally goes into the Brand feels like it could be a reference to Casca's love for her son (who she can feel... through her Brand). It's not necessarily the case, but I could see it happening. Speaking of the Sprite, am I the only one sad to see her go? She's just so cute.

Who knows, though, maybe she's not gone forever. After all, Casca won't have a "Beast of Darkness" per se, but Miura might choose to personify her trauma like he does for Guts.
One thing I did not expect was for Casca's trauma to not be addressed at all. They simply restore her there and then... but with the caveat that the trauma will have to be dealt with afterwards. It makes complete sense of course, as it will allow the issue to be dealt with progressively and over a long period of time. Now the big question is what will this new Casca be like? How will that darkness affect her? Can't wait to find out.