Board Thread:Questions and Answers/@comment-44074436-20191130071403/@comment-38451037-20200108015349

If you complete Genocide, you allow Chara to destory the world.

That's it, no survivors, everyone dies, everything ends.

Chara brings the absolute end to the universe.

And it's all YOUR FAULT.​​​​​​

You can reset the timeline, but at the cost of your player soul (and Flowey's sanity).