Moon Knight/Sailor Moon
Death was boring. And I was hungry. So I stood up.
Teenager Usagi Tsukino was just a girl at the wrong place at the wrong time. While on a class trip to an Egyptian exhibit, she wandered off and saw a couple of thieves trying to steal one of the exhibits. She screamed, and was shot for her troubles. As she bled out, she fell in front of a statue for a nearly forgotten moon god.
That was the day Usagi Tsukino died.
But what she saw on the other side was a white bird man skeleton wearing a tattered white suit and spiders crawling out of its empty sockets. It stared at her and only said one thing.
"You are my daughter."
Then, she woke up and scared the living hell out of her parents and the doctor who had pronounced her dead.
She was called a modern medical miracle. Given such attention at a young age for coming back from the dead with no ill effects. But as she smiled, she planned and trained. Under the direction of her new god, Khonshu, she became the Defender of Night Travelers and Khonshu's fist. She was… Moon Knight!
That was a year ago.
A lot had happened since then.
She has three distinct personalities other than her own. There's Mrs. Knight, the Moon Knight personality which she sorta defaults to later in her career due to the stresses of both the bad stuff she witnesses and Khonshu's influence really work at her. There's Serenity, which is the vestiges of her former life, and Serena Tsukino an undercover identity Usagi uses by disguising herself as an American and hearing the word on the street.
None of these personalities appeared until well within a year when Usagi is clearly beginning to lose her goddamn mind from Khonshu's influence.
(And also keep in mind, the entire point of the idea is that Khonshu is a very foreign entity whose presence is a net negative on Usagi’s life. His existence and taking up residence in her head is slowly driving her insane, )