I Woke Up as a Demon Lord and Became the Master of the System?

[Quick Transmigration · Strong Female Lead · No Romance · System] When Xun Chayuan, the last ancient demon lord, awoke, she discovered that all the lingering souls in the Myriad Demons Banner had escaped. They had transformed into Systems and were running rampant across three thousand minor worlds. Looking at the defeated underlings from her past, she smiled sincerely: How lonely it is to be invincible. Life could use a little excitement. A fast-paced, satisfying quick transmigration story. The female lead is cold and ruthless, decisive in killing, and steamrolls every System in her path. The plot moves quickly, with no romance and no saintly behavior. The female lead has a little morality, but not much. She does whatever she wants. The pacing is fairly brisk, and the worlds are mostly unconnected. Feel free to skip any world you don't like.