Can I Do Whatever I Want with the Power to Rewind Time?

[I couldn't keep writing this, so I'm planning to reopen the old story.]

“At first, Shaoning secretly used time reversal to do a few naughty things. Later, surrounded by friends who trusted her, she gradually grew ambitious.”

Reader's guide:

1. The heroine is neither perfect nor saintly.

2. Alternate history, made-up maps, and a little nation-building. Please don't overthink it.

3. A slight ensemble-cast element.

Theme: Find a way to survive.