It sounds cool and its the sort of thing that makes sense with the lore. Apostate knows he's a Host spirit, after all--he's just inhabiting a dead body.
Given this, you could end up with a neat Etrigan/Jason Blood thing going on where the player is playing both Amaterasu and the person that she's inhabiting...
Which not only evokes the duality types of elements that other super heroes work with between Amaterasu & her... Partner? who's body she's using... But also kind of evokes a kind of magical girl transformation into Amaterasu in my head... which just seems very fitting for a Japanese hero
God, that’s such a better idea. A host spirit that temporarily bonds with people as the need arises! Why didn’t I think of that?
Some info in the most recent LP podcast gives even more support to your idea about the Host, FWIW. Spoilers: In Arataki's universe there's a version of Fanatic called "Anchor" who if I'm interpreting their explanation right can basically let any member of the Host possess her at will.
So, I had another question. So Adam and Chris have said multiple times that OblivAeon shattering the timelines was what made it possible to time travel and hop dimensions. With him out of the way, that route has been closed off.
So, is Time Travel/Dimension hoping 100% impossible now, or is it just really really really hard? Like, no one else has figured it out hard? I know the answer for my game is "It's your game, do what you want," but I wanna know what the canon answer is.
I mean, I'd really like to do something with the X-TREME UNIVERSE! I mean, It's right there. There needs to be some amount of Liefeldianess in my comics. I mean, they are COMICS.
I mean . . . I guess Wager master could temporarily make the core universe (or a small set of it) X-TREME!
Outside of Wager Master we don’t of any character that can travel between Multiverses and we don’t have any known time traveling heroes post OblivAeon.
I'm thinking it's actually "nobody's figured it out" hard, as it makes more sense to me now that I think about it that OblivAeon was able to maximize on something that already existed as a possibility in the universe's structure versus putting something entirely new into the universe's structure.
Of course... that also kinda still means that it initially took someone on the power level of OblivAeon to figure it out. :>
If you just want "some amount" of the XTremeverse in your games, it might possibly be easier to do the reverse and handwave that some of the XTremeverse heroes got trapped here after trying to help since we already know that people getting stranded in different universe has actually happened. We already know the XTreme Prime Wardens at least came here, so I see nothing wrong with just pretending one or more of them ended up stranded here, or that more heroes from that universe also came to help out.
You know, there's no reason you can't use the exisiting pieces of the universe to open up all the alternate-timeline/reality shenanigans you want. Yes Wager Master is an option, but there's plenty of other options like a scientist using OblivAeon Shards to power a portal generator, or maybe a new NPC hero/villain arises that has a special power to move between realities...
It's all how you use the lore to your advantage.
We also know there are other singular entities out there, such as Faultless before his fall and Galactra’s patron. You can invent others. Plus the energy and matter that made up OblivAeon didn’t completely vanish.
So, another Lore question. I know they say that the way magic works is not well defined. But I was wondering what we do know. The way Mr. Fixer can deal radiant damage (in canon he, as Black Fist, did that to defeat a bunch of Vampires); does that count as magic? Are there ‘ki’ abilities in Sentiels and do they count as a type of magic, or are they their own thing? Are there other types of magic besides Nightmist’s ‘European-style’ magic and Scholar’s Alchemy (assuming the virtuoso is his own separate unique thing.)
Is there technomancy? Shinto spiritualist magic?
Mr. Fixer's abilities were described as "Punching Plus" during his Letters Page episode, though there are some oblique references to his ability to sense the flow of chi and use that in place of actual vision. I wouldn't call him a magic-user, but his martial arts abilities have exceeded human knowledge and breached into the realm of supernatural.
Known current types of magic include:
I'm likely missing a few, but those are the big ones detailed so far. Unity is, technically, a technomancer, though she is unaware of that fact.
And on that note, there are also chaos witches like the one that ultimately gave her her powers, and I think we know precisely nothing about them.
I don't even know if they count as magical. c.c
Did we ever get confirmation if there’s a difference between discordian magic and chaos magic? I can’t remember…
I know I sent in a Letter Page letter about chaos witches once upon a time, but I have no idea if it got answered. ;_;
My biggest question on magic in Sentinels is do you need an innate spark (like Dresden files) or is it more cause and effect, like if you follow the ritual correctly you always get the same reaction,
I think that's the difference between someone like Argent Adept (who had a unique, innate disposition towards Void magic) and someone like Nightmist (who acquires magic through study, arcane relics, and ritual).
To me, it's kind of like the difference between a Sorcerer and a Wizard in D&D. AA's a Sorcerer, while Nightmist is a Wizard.
(Yes, I know he's a bard…just follow the analogy. 
)
That makes some sense but Nightmist has that boosted stuff going on from the Mist part of her. I dunno, either way i'll probably just fudge it so my character idea works anyway lol
Dark Watch Nightmist multiclassed. 
I admit I'm still eternally confused about how Void Magic works.
If you're not supposed to mix Void Magic and any other type of magic, what about Nightmist's eventual deal?
With the Virtuosos, do different phrases produce different effects, or is it a looser "you play anything just to focus Void power into whatever you think up" sort of thing? What exactly happens to change things whenever Argent plays more than one instrument?
For that matter, why is Argent weaker than the other Virtuosos who only played one instrument? Related to that, it's clear that what he's doing in Tactics is Not The Right Thing, but why, exactly? They mention how he's lacking in knowledge, but never really specify knowledge of what, exactly. Knowledge of how to play and channel Void energy properly (which I guess then ties back into my second question above), or is more like how Marvel's Victor Alvarez's powers work, where the knowledge itself is the source of power?
And what about Visionary who has an obvious measure of control and connection to the Void despite being a psychic?
(I've asked some of this stuff on the Letters Page at various points, but so far haven't had any of it answered, to my disappointment.)
You're not alone in the confusion regarding the Void.
I don't think the other Virtuosos only played one instrument, though; I'm pretty sure that they had access to prior instruments as well, though I have no confirmation of that whatsoever. I may well be erroneous.
Visionary brings up a weird interaction; I'd like to see some answers in regards to how psychic powers (which seem to be intrinsically linked to mental trauma) work in tandem with magic (which has a number of sources).
Maybe we'll someday get a "Magic in the Multiverse" Letters Page episode...