When I first saw Requiem in the church...

I didn't notice back then but... Looking back now, the direction of the shadow was unnatural.

The next time I saw it, I was in a state where I could only see the souls of living things.

But Requiem's shadow was clearly visible to me.

In other words, Requiem's shadow is the shadow of the soul. And the light source is the soul of each of us.

So it's like a shadow that looks like it's stretching in the opposite direction no matter from where you look at it.