Wow, these certainly are exciting times!
I caught the term "mana" during my transcription of 323. I didn't think much of it before, but now in light of 324's translation, I see that it really is a new, named concept for the series. However, I wish we'd gotten a glimpse at how this all works. It's one thing to have Ivalera lecture Isma (and us) about it, and quite another to see the concept in action.
Forgive the quote-post, but there were three big posts to reply to... No easy way out!
I wonder how that notion of Mana will be used later on. We're probably going to hear about it again in Elfhelm, and I wonder how the whole "having power over astral beings" thing will work out. Will Guts find astral allies in his battle against evil, like some have been speculating for a long time? Could it be used by some characters for nefarious purposes, like Ivalera warned?
My first thought was that it would be used by citizens of Falconia, who could learn to control astral creatures that would otherwise be a threat. They could essentially seize control of them, using this, instead of a creature trusting someone enough to lend them their name/power.
Would it work on the God Hand? Imagine Guts yelling "FEMTO!" at Griffith, resulting in his transformation. 
I'm certainly not going to exclude that as a possibility, but I just don't think the God Hand are fundamentally the same as astral creatures, so I don't think the same rules apply. However, as always, what we don't know about the God Hand could fill a book. Whereas what we
do know can barely fill a thread.
Also, was I the only one to think that Puck's reaction to that information was as ambiguous as ever? It reminded me of his strange nonchalance when the group talked about the King of the Flower Storm in volume 28. Could be nothing, but...
I hadn't even noticed that, but now that I look at it, it doesn't appear to me that he's playing coy. Though I'd be interested if there was some history between him and this concept of true names.
On a side note, my favorite reaction in this episode was, as always, Magnifico. :ear:
I have also wanted to see his actual transformation process from his human form to demon form. The closest thing we get is from the lost episode.
Yeah, but I don't think that can apply in the way you mean. He was in the process of shaping his form in that scene.
I could see Skullknight shedding some more light about how how true Names work with powerful astral beings like the God Hand, or even just ones like the Dragon we saw on the castle when the merging took place. Schierke will have something to say about this for sure as well.
I don't think the Skull Knight necessarily needs to show up and weigh in on it, though that'd be nice. He's more of a master of riddles than he is a walking encyclopedia.
However I don't see Guts and co. running around, reading Names from a long scroll of true names that was left in one of the elf kings chests.
I don't see that either. But who says it has to play out as ridiculously as that? There are a huge number of ways this concept could be implemented in the future.
That aside, I think Guts will be more injured than ever when this is over. The trip might even take it's toll on Schierke as well.
But why? It's just her astral projection out there with Guts, and she's being guarded on the Sea Horse. Of course, everyone on board is in danger, but I don't see any reason to single Schierke out. I also think saying Guts will be "more injured than ever" is an exaggeration. He hasn't lost any limbs yet.
Skullknight and his Sword might be the only way out,
That doesn't sound very practical. We're talking about a huge crew of people here. Now that you mention it though, I wonder how effective that sword technique is now, with the state of the Berserk world...