What caused visions seen by Saki?


During the series, Saki often sees really weird visions, sometimes very
phantasmagorical. If I remember correctly, first time was when she was trapped
with Satoru after encountering hostile bakenezumi.

So, to put it short - what was actually source of her visions? It's clearly
not normal for human to see things out of nowhere. I may understand why she is
seeing visions after

> Shun becomes Karma-demon (may be impact of his power on her
> brain/subconsciousness or something),

but not for first time at least.

