When I Wake Up, I Am a Demon and Become the Master of the System?

[Quick travel·Big heroine·No cp·System] When the last ancient demon leader Xun Xianyuan woke up, he found that all the remaining souls in the demon flags had escaped. They incarnate into the system and dominate the three thousand small worlds. She looked at the defeated generals before and smiled sincerely: How lonely it is to be invincible, life just lacks fun. It's a quick read, the heroine is cold-blooded, decisive in killing, pushing all the systems along the way, the plot is compact, no cp, not the Holy Mother. The heroine has some morals but not much, she can do whatever she wants. The pace is relatively fast, and there is basically no connection between the worlds. You can skip the world you don't like.