"Some centuries ago," she begins, voice low and grand, "I began a project - to build a god of my own. To feed it, I would need trillions of souls... Something rather simple, if I merely stole from the dead. I found and modified an artifact, to steal those souls and crystallize them."
"This apparently attracted quite a bit of ire, especially since it also stole the souls of the resurrected. I constructed a grand tomb complex to house my godling, to draw in powerful adventurers I could kill. And also because grand tomb complexes full of traps are funny."
"Unfortunately for me, I apparently drew the attention of a multiversal group, who allied with one of the resurrected whose soul was growing looser and closer to being stolen by the hour. They infiltrated by complex, bypassing many of the traps in a way I'll have to prevent in the future... And they actually got to my central room, challenging me. One could manipulate the blood of my little godling. One could manipulate reality to give her friends an edge. One could challenge my mastery of the undead, albeit weakly. Two had quite an entertaining array of powers - which proved my downfall. I played with them for a bit, you see, and moved early to try and rip out the heart of one of the more powerful members. She survived, but I thought I'd effectively removed her from play... Giving me time to winnow down her friends."
"She objected to me ripping out another's heart - the blood manipulator, who was being exceptionally obnoxious - and used a powerful ability to sacrifice her own life, blowing open the gates of the realms of the dead and resurrecting both her friend and every single soul I'd accumulated. I let myself be beaten back, after that, as I know when to give ground, and let them believe they'd killed me permanently."
"It seemed wise, after that, to avoid places where my face was known, so I picked a world at random - coming here."