OK, i don't know why, but i suddenly asked myself:
"If the Stuff is that feared with only touching, then what happens if it's injected?"
Is this a 100% safe way to make magicians of any kind mundane?

You're assuming it would be able to survive let alone thrive if injected into a living being.

Well, FABIII lives on mana alone right?
Where would you find that, if not inside the body of an awakened?

First of all, it's dual-natured. It's as much physical as it is astral. Second, if it did thrive inside a living body, it wouldn't just sit around chilling on your skin. It would seep in through your nose, mouth, ears, pores, and other orifices and have a field day. It can also be starved into submission just by going fully mundane. Sterilize and Cure Disease both work to destroy it, and while the rules don't mention medical science at all (meaning, they don't say its possible or impossible), it stands to reason that more traditional means of dealing with a disease would work just fine. Including your own immune system should it be injected into you. Even though nothing in the rules even hints that it works as an internal disease or infection at all, which is probably why they never talk about medical science.

So, yeah, there's not really much there that even implies that it would do anything spectacular if injected. There's also nothing saying it wouldn't, but the implications I get seem to suggest it wouldn't live for very long if at all. And even if it did, all of the same means of ridding yourself of it -- going mundane, Sterilize, or Cure Disease -- would function just the same.

It would probably cause an embolism.

I'd go with that. Injecting just about any random substance into the bloodstream is likely to kill people.

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?

I see you have many questions. How could such a glorious opportunity be hidden from you for so long? Is there some vast conspiracy to keep you from developing your own talents? What nefarious forces are behind this conspiracy? The answers for these, and many more questions, await you this weekend at our retreat. Please, come be our guest.

I am a Troll.
I can throw motorcycles.
I'm good.

One could load some nanos with FABIII. But I have no idea what would happen.

Toiling under yoke?
Mundane in a magic world?
Trust Gaf to free.