A large content datapack that makes all mobs in dark areas Shadowforms, and adds all sorts of features around that mechanic.
Shadowforms are more powerful, faster and surrounded by a large cloud. They can be found in dark areas, but when in light areas, they'll get really weak.
Shadowforms sometimes drop blackened hearts, which can be used in multiple rituals. Wonder what's the origin story?
The mechanical altar is a new block that can be used to damage nearby mobs. Just power it and let it do it's magic!
There are 5 structures in Shadowforms which can be found deep underground. Pictured is a shrine with a strange treasure inside...