I don't know about Sparda though. Is he not dead in your universe?
Yeah, he was pretty much dead. It's the only reason I could ever fathom why he wasn't there to protect his family. But because the Order was watching over him and everyone else, they were able to retrieve his body after his death, which explains why his body was never found. In my mind, though, it would have taken a lot of damage to bring Sparda down, so his body would have been short of mutilated, but because the Order had his DNA at their disposal, it made it possible for them to clone him.
I did have some questions about him as well. Like how does he have the power to give humans immortality and a place outside of time to exist? Those things never occurred to me, him establishing an order of immortals, although it would make sense if he established a secret order that was passed down for generations...Ah, but Manny and I have too many orders to think about right now.
In a way the humans aren't exactly immortal. If one of them tripped and fell down the stairs and broke their neck, they would probably be paralysed for life or dead. This is one of the things I didn't properly define for the reader in the fic. The place where they find themselves is an underground safehouse of sorts, or rather an underground 'safe-city'. It was built by humans and demons alike when Sparda first established the Order, so it is a real, solid place. What Sparda did was to conceal the construction from demon and human alike, and to do that he pierced the veil between the worlds and found a little hole that just happened to be a timeless space. And the magic itself in the safety zone are all Sparda's doing, and not entirely what it seems (which again, I didn't really explain well in the fic) Like, the green ward that kept Nero captive in that room was actually a ward that surrounded the rest of the facility, and not the room itself. It only activated because Nero was angry and intent on exerting violence on the others. That's why, when he was moved to the new room, the ward was there as well, it just wasn't activated because he'd calmed down and wasn't planning on stabbing someone. And again, the whole purple explosions that happen when they try to fight one another, is not a spell cast that prevents harm between members but it's rather a...protective shield? Er...how do I explain this...it's like Sparda's mark on the people. They're basically protected by his power as long as they remain loyal to him. And from what I know of magic, even pitiful human beings can use it if they know how, and it is very much influenced by emotion, which is why the magic itself is subject to change according to mood swings, and why it's as easy as pie for Sparda to do.
I could never see Sparda sealing away ALL his power, I mean logically if he was as powerful as the legend implies, he would still have some excess of his power in human form. And, of course, he must have had a broad knowledge of the demonic and mastered the dark arts, so even if he didn't have that much of his own power, he still had the intellect to know how to get things done.
Also, what is the basis for this magic? Is it demonic, angelic? Something of both, or alchemy? These kind of concerns are my forte, so I'm interested.
I think I've already kind of answered that, but to expand on it a bit (because of my beliefs, etc) the magic is derived from the demonic. Angels wouldn't risk giving any of their power to humans because human nature is evil, but demons would grant wishes and give access to their corrupt powers to the humans, because they really don't care whether it is used for good or evil. Because the power is corrupt (demons being fallen angels) it is presumed that eventually the wielder of the power will also fall into corruption at some point. So on that, the basis for the magic is demonic.
Also also, have you made any demonic characters or altered anything about the standard history of Sparda?
Not that I'm aware of. I try to keep within the legend, and when I bring other elements into play it's in a way that won't contradict the actual legend or have any effect on what is canon. But demonic characters, yeah, I've got a few of them, but none of the canons from the games since they're all either dead or too butt-hurt over what Sparda did.