Project Amaranth is a science fiction superhero universe with TG elements I created back in 2012. I don't remember the exact reasons why, but I just got into it and built the setting. The TG elements aren't the primary element in the stories, but they are key to the characters they affect.

The setting takes place in time referencing fictional events from as far back as 20,000 years ago, to around the year 2130 with a few scenes spread across time after that all the way to the inexorable heat death of the universe. The locations the Amaranth stories take place in are primarily Earth and a few nearby planets within a hundred light years. There are locations referenced which will be farther away, or implied to be farther, some at thousands of light years distance from Earth.

I don't think I'll ever open this universe up for others to write in, but I have entertained the idea. I may do this anyway, once the stories I know I'm going to write are finished.