Dark Hero. Fourth Chronicle, #2

Sia Wong has no memory of before she was a baby. That is because she was someone else that became a baby because of some overflowing powers. Sia goes to Med School in Seoul Korea and after works at Busan Hospital. She is a chaebol's granddaughter and that leads to issues with paparazzi and the hostile takeover of her grandfather's company. Many of her patients die because someone interferes with her job and so she is forced to join doctors without borders and her body goes missing and she is presumed dead.
Sia or Akiyo comes back to her senses and is a grim reaper. The gods are all dead. The pandemic of 2020 happens. A space ship hits the moon and lands on earth. The water rises. She ends up being frozen to save her from super hero induced cancer and wakes up without the memories of her reunited soul one thousand years later.