Cepheus is prominently featured in the Perseus legend as the husband of lovely Cassiopeia and father of Princess Andromeda
Cephus can activate Andromeda on-device for devices on Android 8.0+ who want to use Substratum themes. As of now, this app requires root to work.
I know to some this may seem counter-intuitive, since the main selling point of andromeda is a rootless substratum setup. However, some users are on a rooted Oreo and use Andromeda for certain themes that don't play nicely with Android 8+.
Eventually, this will work on an unrooted device if I see enough people requesting it. If you would like to see this support unrooted devices, go to the issues and comment on the issue for unrooted support. I will use this as a gauge-of-interest.