This is Megan Yan, a human living in New earth.
A year after her graduation, her friend group has to defend their town from otherworldly invaders as everything crumbles around them, during this journey she discovers she has a supernatural connection to the dead, she explores this power later on when she becomes an adventurer.

She is affected by Warping, (info here: https://www.furaffinity.net/view/54976056/ ), which has made her hair start to gray, and turned her eye red, she lost her other eye to a particularly violent warping dream.

(Other two humans mentioned are Izzi, and William, I will be posting them another day)