. . . in which I answer questions related to those parts of Imperial Mysteries that are not Dave’s to answer.
What happens when an archmaster removes the conditions that allows a previously Ascended being to exist?
This depends on the rationale for Ascension. Most Ascensions are pretty durable because an Ascended being exists in a state more fundamental than the Phenomenal, but if they depend on a recurring relationship with the Phenomenal World, it might be possible to dethrone them. This is the sort of thing that brought the Abyss into being, however.
What’s the deal with the Aswadim? They don’t seem so bad.
The Aswadim want to enjoy a spiritual state that allows them to embrace fundamental contradictions. They want to be Hypocrite Buddhas. This is different from knowing a fundamental ground of being prior to categories of existence that may seem contradictory, but can be resolved when you’re enlightened. This isn’t really the same as giving everyone their private universe. It’s more like giving yourself an insane private universe and telling everyone else it’ll be totally cool, unless they’re weaklings.
Is there a way to protect your Imperium Rites from outside interference?
There’s no direct method. You need to adjust the Force you’re pushing into the rite to avoid Aponoia.
What happens when you fail to seal an Omen?
You can’t use it until you seal it. You may design new challenges at a +1 difficulty increase, as per p. 78.
What happens when you fail to Exalt an Omen?
The changes it represents fail to occur, and you don’t Ascend. You may keep trying, but Aponoia may add additional Omens to seal and Exalt to get your plan back on track. Eventually, it may become impractical to continue, as Arcane Experience, Willpower dot and eternal wound costs repeat themselves.
Incidentally, you can’t heal eternal wounds, as far as I’m concerned. Dave may be more liberal about this. Archmages who’ve repeatedly failed probably sacrifice their Physical and Social Attributes first, followed by Wisdom, then finally Gnosis. I can’t think of a more pissed off entity than a sorcerer who’s insane, crippled, and whittled down to Mastery after reaching too far, too often.
Can you change your Omens?
Yes. See p. 77. One common usage is to shake off Profane Omens, since you can’t progress toward Ascension until to finish with them.
So, what can other supernaturals do about all this reality editing?
I assume they can do something, but I don’t know what it is. I personally think the ways in which other supernaturals interact with Imperium is unique to each type, rather than there being corresponding arch-vampires and arch-werewolves. Remember that Imperial Mysteries includes the option that archmages aren’t really altering reality for anyone else — just themselves.
In terms of the wider World of Darkness, the book assumes a kind of Anthropic Principle where the universe necessarily includes the conditions under which other supernatural beings exist. I don’t know why it might be that way and frankly, it’s none of my business. It’s your prerogative.