Maybe the (totally not a DOS2 repeat) scene at the end of the intro where a mysterious force saves you from dying is supposed to imply the shadow magic being inserted into the tadpole?
I thusfar suspected Gale for being responsible for that, but I have no other reason to think that, besides; "A Wizard did it" - Oh, and tht he mentioned me lying somewhere, so he thought I was dead. He could of course mean, on the ship itself.
I have a suspicion Gale was never on the nautiloid.