Hey! I made sure to mention in the post that the free DLC will launch alongside the next patch, because all the code that hooks Kageshini into the main game has to be IN the main game so it knows to check for her. If I put it out now, it just wouldn't work because the main game doesn't have the code that checks for her yet.
We'll release Kageshini with her own page on Itch.io alongside the 1.6.0.0 release for the main WCA game :)