The Apotheosis Event
After the events of September 21st, 2012, during which time Hazel Ninegate did battle with the Black Guardian and partially succeeded in integrating his powers over Spacetime, wreaking havoc with the timeline of Earth 1337-A until she was finally stopped by the united forces of The Hotel at the cost of an entire day all throughout the universe, Hazel was mortally wounded.
Still in possession of some Guardian Powers, she made it back to the Hotel's library, where she did some research on Alchemical Studies from alternate universe Earth 1908-FMAB, wherein she discovered a means to preserve her own life-- the creation of a Philosopher's Stone.
Traveling to Veridian IV, she managed to use the corona of the Veridian Sun as reflected behind the planet during a Solar Eclipse, in combination with various points of power she had established all over the globe, to create a gigantic magical circle within which 99.8 percent of the population was trapped as the planet turned on its axis.
Brutally murdering the populace, she extracted their life energy and created a Philosopher's Stone, which she consumed, repairing her body, and giving her untold powers-- powers too great, in fact, for her body to handle.