Read up to the last chapter Miura produced.
Griffith's dark hair confirming he physically transforms into the Moonlight Boy is a major reveal. It does raise the question on how it didn't happen several other times with a full moon such as when he took Charlotte, though I'd assume it would've been revealed it was only during the strongest of full moons it happens or in random intervals. Also, I'm guessing that him going to Elfhelm in the boy's body would've been the inciting incident of war being brought to Guts' party even if they didn't seek it.
Casca's trauma helps further showcase that regaining her memories wasn't a quick fix, though her return to her intelligent personality is still good with her also something some change when it comes to her responses to characters and being far less reserved than she was in the Golden Age. Chapter 362 has easily the biggest reveals within the arc with us learning more of the Berserker Armour and it hammering (no pun intended) in the message that how people use something has more impact than the object itself, with the reveal of the previous God Hand being the most shocking part of the arc. It does somewhat contest with the theory that the God Hand may not have been the ones to destroy Gaiseric's capital due to the issue of the amount, though the position of all the skulls being branded and the natural forces that destroyed it are still questionable aspects.
Even though it would've been great for Miura to have gone further, I can appreciate Guts had still mostly succeeded in his goal at that point and was in a peaceful place, though it was obviously far from closure with reveals such as Flora's role in changing Danan's body or attaching Gaiseric's to the armour as well as the impending threat the Moonlight Boy would bring. Shame a lot of the chapter is bogged down by Isidro's filler antics.
So, we reach the inconclusive end of the Fantasia Arc. When not having the inconsistent release schedule as a factor, the arc itself is fine. Things such as the Sea God could've been skimmed down heavily and the attempts at humour from Isidro and Puck could be a bit distracting from the pacing and darker events, but the arc wasn't bad with us getting some of the biggest reveals in a long time such as Casca regaining her memories, Skull Knight being confirmed as Gaiseric or the reveal of the previous God Hand. It was a decent set up for events, even if many of them won't be delivered on. 6/10.
Now, the most we can probably do is speculate on events that covered been. Along with the invasion of Elfhelm, I imagine the Moonlight Boy would've been integral to Griffith's defeat or Guts' fate. Guts has a few elements similar to Norse mythology such as losing an eye as Odin did, losing his arm as Tyr did to Fenrir and the concept of the Berserker Armour overcoming him being similar to Odin being eaten whole by Fenrir only for his son to slay the wolf. Perhaps the power of the armour would've overcome Guts during the apocalyptic endgame of the series and the Moonlight Boy would stop him either by helping him finally overcoming the Beast of Darkness for good or by force. Unfortunately, all we have now are theories. RIP Miura
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