you're the only one

1 -- Watsonianly the purpose is to mark them as sacrifices that belong to... ghosts and demons and beings of the astral plane. Narratively it has fallen by the wayside since Flora largely neutralized it.

I believe for most of the story it was the explanation for Guts' Beast of Darkness, a lot of his implausible strength and fighting ability, and his theoretical ability to defy fate - Skull Knight explains that the brand puts him a step outside reality, giving him one foot in the interstice. The conclusion I drew from this based on other Berserk worldbuilding was that Guts' astral body, which sort of like reflects his psyche I think, has an influence on his physical existence, allowing his own rage/inner darkness to power him slightly and gain form and voice.

However! It seems that has been dropped or I was wrong to draw those connections lol because our new explanation is that Guts was just ~born that way. So now I don't know what the brand is for. Maybe we'll see someday.

2 -- The answer to this is basically just, that's how Miura wrote it. I'm not sure what you're referring to specifically by everything getting worse though - he did have to fight a bit of a war with Ganishka? I wouldn't say that was worse than the Conviction arc status quo though. Then he fused the real world and the astral world, resulting in fantasy creatures roaming around everywhere, if that's what you're referring to. He did that to give humanity an enemy to unite against and make Falconia a safe place people would flock to.

And apostles and the Godhand are different beings, so the rules are different. The Godhand are beings of the astral realm or whatever and could not physically manifest in the real world without reincarnating the way Griffith did, but apostles are physical beings in reality. It's not just about Femto/Griffith changing form, it's about physically existing.

3 -- The behelit Guts is carrying, or all behelits? They're magic stones that allow for people to make a sacrifice and become a monster or, if they get the extra special crimson behelit, a Godhand. The behelits do this by essentially opening a tunnel into the astral realm and allowing the Godhand to appear. The behelits are also indications of fate - fate dictates where a behelit is, and ensures it eventually falls into the hands of someone fated to become a monster or demon. Guts' behelit is an ominous sign that Guts, or someone close to him, is likely to make a sacrifice and become a monster, or at least get the opportunity to do so after falling into despair.

Narratively Guts' behelit serves as foreshadowing and a reminder that Guts is never too far from becoming a monster.

As for the second half of this question, pre-Fantasia arc, witches and monsters and elves etc existed but were scarce. Puck explains at some point in the Conviction arc that most people can't even see elves and stuff like that because they have no belief in them and no experience with the astral plane. Farnese is only able to see Puck after having her worldview rocked by a bunch of magic shit happening.

Witches, as we see with Flora, lived isolated lives using magic to be hard to find, so it makes sense that we never saw any during the Golden Age. Guts and co start seeing more magic stuff post Golden Age because Guts has a foot outside reality after the brand and the sacrifice, ghosts manifest around him thanks to the brand, etc.

So yeah, these magical beings live away from humanity, in their own little pockets like Flora, mostly invisibly like Puck, or in big communities like Elfhelm, closed off to regular people.

(Yeah we were introduced to Puck because he was being tormented in a bar and Guts saved him - Farnese being unable to see him because of her initially rigid worldview was probably kind of a retcon. But you can explain it by suggesting that since the town Guts is in in chapter 1 is being terrorized by an apostle, maybe that area is more open to seeing magic.)

4 -- Plotwise, the Ganishka conflict introduced a few things that are relevant now, like Daiba, and Kushan in general. It established NeoGriffith's attitude towards humanity and his general vibe. It also allowed NeoGriffith to become a big hero who saved the world so that many people would follow him without question. Ganishka's leveled up form, Shiva, provided an apocalyptic threat that allowed humanity to unite and ally with apostles, and killing Shiva allowed Griffith to fuse the real world and the astral world, bringing fantasy creatures into reality to further his goal of building an empire.

Thematically it also provides a contrast to the 100 year war in the Golden Age, showing how powerful and untouchable Griffith is in comparison to his human self, but also how empty he is. The fact that it was an easy victory for Griffith with very little tension is a way of separating him from his more vulnerable humanity.

Honestly I enjoyed that half of the Millenium Falcon arc much more than Guts' side of the story so I'm glad the whole war plot was there.

5 -- We don't know what Skull Knight's role narratively is yet, except for being an occasional mysterious guide to Guts who shows up to explain stuff sometimes. There are hints here and there - we know for sure now that he's the 1000 year old former emperor of Midland, Gaiseric. We don't know if he was a former sacrifice like Guts, if he was a former incarnated Godhand. We do know he used the Berserk armour too much in the past and it fucked him up. We know his goal is to trap the Godhand in the "vortex" they're called to when someone makes a sacrifice (presumably inbetween the astral realm and the real world), as he explains in the troll cave scene with Slan, chapter 218 or thereabouts iirc. Flora suggests he's using Guts for his own ends. Eventually we'll probably learn what his whole deal is.

6 -- The Berserk armour was made by some dude we meet in Elfhelm, and it gives the wearer superhuman abilities by essentially removing their ability to feel pain and allowing them to fight through broken bones and stuff. This is dangerous to the wearer, and it saps their lifeforce, and without a lot of magic help is liable to essentially take over the wearer's humanity and turn them into their inner monster. With Gaiseric his representation of his inner darkness was a skeleton, with Guts it's a hound.

So it has a lot of drawbacks theoretically and narratively it allowed Guts to kick more ass and gave Miura room for more epic fights with more scary opponents, while still creating tension through the threat of Guts losing his humanity and becoming a monster while wearing it.

But since that still hasn't gone anywhere and Guts is fine, I do think it ended up just being a convenient RPG power up lol, unless something dark still happens with it in the future.

7 -- Kinda both? It's literally given form thanks to Guts being a step outside the real world after the Eclipse (or because he was born that way, whatever) but it is a manifestation of Guts' trauma and rage. It essentially represents the part of Guts that wants to fight so he can lose himself in battle and not have to think.

Which is basically his coping mechanism.

8 -- We don't know for sure but with the recent chapter it seems like Griffith kidnapped Casca for the same reason he invited Rickert to join the Hawks, ie he's lowkey trying to recreate a piece of the past he destroyed. I'm sure that's not the logic he's using consciously - maybe he tells himself he wants her as bait, or as someone who can babysit him when he werebabies out lol. But he seems to be missing the past just as much as Guts does, and I guess Casca represents that to both of them.

As for moonbaby, best guess is it's the fetus that was created when Guts impregnated Casca, then Casca got raped and miscarried the now demonized fetus, that fetus was eventually used to create NeoGriffith's human flesh (when he hatched from the behelit-apostle at the end of the Conviction arc, after that apostle ate the fetus). And now on the full moon, when magic is most powerful, the spirit of the kid takes over his body or whatever.

It sucks imo.

8 -- I like Sonia. I think she's funny, and she represents one of my favourite themes of the story - the isolation and loneliness of seeing the world differently/being on another plane of existence, which parallels Griffith. She also provides opportunities for Griffith to be more personable and patient and basically normal-seeming, which I enjoy seeing. Not necessarily because it's genuine, but because it shows that he's not just an aloof saintlike figure, he's also able to be likeable.