Demon and Nedge haven't actually explained how The Space Between Time is stronger than Etherion. That's never stated, implied or even brought up BY Zeref. Furthermore
upon obtain Fairy Heart and the Space Between Time Zeref stated that'd he'd go back in time and kill Acnologia before he was as strong. This Acnologia is High 6-C and even with Fairy Heart and Space Between Time Zeref knew he wouldn't be able to defeat Acnologia. Quiting Zeref and Mavis here.
"I fear him because I cannot die! I can't beat Acnologia even as an. Immortal!"
"But I make you a promise. Long before he becomes as powerful as he is now I'll kill Acnologia"
This heavily implies that Zeref wouldn't be able to kill Acnologia head on, who's High 6-C at this point. He'd have to time Reset, find a weaker version of Acnologia and kill him before he gets too strong. Keep in mind this is Acnologia when he was only
High 6-C it's like going back in time to stop the world from getting destroyed or traveling back in time to paradox someone so they'd never exist. That being said we have two direct statements from Zeref that even with both Fairy Heart and Space Between Time that he'd still lose to the High 6-C Acnologia. Two of them that work together very well.
All the Space Between Time does is give the user a boost in Magic along with Time Magic.
, Fairy Heart is the same thing more or less. Fairy Heart doesn't scale to Etherion, it has the ability to launch Etherion if the user so desires but there's multiple things wrong with this. The first being that nobody in the series can be scaled to or above Etherion since it's not in use anymore, was never stated to be unable to defeat someone and given the fact is Fairy Heart scaled to Etherion then it wouldn't have the ability to fire Etherion. If Fairy Heart was High 6-B by itself then it wouldn't have the option to spam Etherion, because it'd be utterly worthless. They both grant the users boosts in power yes, but it's nothing compared to power of Etherion. While you can argue that having more magic equates to being stronger that's easily countered by the fact that Fairy Heart is an infinite amount of Magic. Thus making Zeref High 3-A. As a side not I'd rather not hearing the argument that Fairy Heart not having infinite magic being hyperbole out of this. We all know it's not, it's stated numerous times in the Manga by knowledgeable characters. It's either that you go with Etherion having infinite amounts of magic or simply scrapping the entire argument that Fairy Heart scales to Etherion all together ( It doesn't but for different reasons obviously. )
Scaling such a thing to Etherion would be incorrect given how vague it is and how it's never implied that Fairy Heart is >>> Etherion. It's further backed up by the fact that Lucy and Co were able to seal away Dragon Acnologia via Fairy Sphere,along with the mages on the area. This isn't a showing of AP, it's a showing of hax. Which is how Fairy Heart and The Space Between Time works, they aren't something that can boost the user to Etherion. They're making the user stronger than they were before, supply magic and grants new abilities. To suggest that either one scales is dishonest and ignoring in verse statements, again If Fairy Heart was stronger than Etherion then it wouldn't have the ability to fire Etherion endlessly. Because that's its strongest ability. What everyone seems to be confused about is that they think Imade is suggesting they didn't get stronger. They certainly got stronger but not to the point of surpassing Etherion.
- Zeref states that even with both that'd he'd only be able to beat the High 6-C Acnologia via time Reset and killing him before he got that strong. Meaning Zeref was scared by High 6-C Acnologia in canon.
- Fairy Heart doesn't scale to the DC or AP of Etherion. It's never been stated or suggested, and if it was then there would be absolutely no need for it to have the ability to fire Etherion endlessly since Fairy Heart would already be stronger than Etherion by itself going by this logic.
- The Space Between Time is a non-argumemt. It's never even stated to be a massive magical reserve, it's vague and all it does is supply Time Magic. Acnologia himself couldn't even scale to the full thing, he had issues even controlling it with him getting his soul and body separated as a return.
- High 6-C, likely far higher is the best solution is the best these characters should get. Given how it's much more consistent than High 6-B, makes sense for scaling and we have direct characters they scale above. Now that Imade and several users explained what Fairy Heart and the Space Between Time does I think it's the better option. The conclusion is that while both give the user a boost in AP it doesn't bring them up to Etherion level which is never stated or implied. If Fairy Heart was stronger than Etherion then it would make zero sense for it to be able to spam Etherion, and the Space Between Time is literally never brought up in the same sentence as Etherion. It's a magic supply but we don't know how much Magic is in said supply and we're never given exact statements about it even being comparable to Etherion. It's clearly much below that. It seems like these characters have been upgraded due to misinformation and confusion on how they work. Which is easy to understand, given how vague the Manga is on how Etherion would interact with others. But the scaling is clearly wrong and should be removed for the various reasons that Imade and myself have brought up.