Whether it was her stronger magical background or by the simple expedience of being mentally prepared, the skull's whisper didn't smash into Fia quite the same way like the noblewoman a moment earlier. Still, there's significant difference between hearing about it and actually experiencing the effect. Her perception of the world itself warped, color taking a slightly more monochrome tint that wavered at the edge of her sight, indistinct echo of a primal chanting that was more felt than heard, the skull and dagger standing out by being the only thing that remained indifferent to the warping effect.

The mental effect was much more insidious, soft caress that would be easy to miss if one wasn't prepared or focused too much on the immediately perceived distortions. It was a soft caress at the back of one's mind, subtly trying to guide and change her value, to make death seems like the most appealing goal she could strive to. Fia could block it out without too much issue right now, but it's a constant effort to do so. If a mage of Theriadore's caliber had to erect a containment field to study the artifact for prolonged period, perhaps similar display of prudence was a wise thing to do.

Nevertheless, directly handling the crystal skull didn't cause any notifiable change. It was lighter than it looked, the inside hollow like a disconcertingly perfect replica of someone's skull down to the slightly assymetric nature of a natural one. Wearing it as a necklace would still be cumbersome, but not impossibly so.

Meanwhile, the dagger contained a more direct hungering for life upon touch. It was similarly easy to block, not dissimilar to ignoring the pounding of a light headache, but the black glass itself hungered to be wielded. Fia could see the herself slicing forward, feeling the grisly sensation of the glassy edge biting into exposed jugular, the warmth of lifeblood spraying on her face...

...a blink, and the image was gone. Only the ravenous hunger remained, contesting the skull's pull to plunge it on oneself instead of on others. The balance was tenuous, but perhaps that's how the previous wielders remained sane? For some time, at least.