This involves two origins. The 'Dark Titan' origin is unavailable through the selection screen. Instead, you must upgrade the 'Void Hermit' origin into it, by getting the advancement 'A Furious Cocktail'. Be warned, the origin is terrible until you upgrade it.
Void Hermit: 🔴🔴🔴 Void Hermit Origin Info
Dark Titan: 🔴🔴🔴 Dark Titan Origin Info
Make sure you have these mods installed as well as Fabric for 1.20.1:
- fabric-api
- origins
- pehkui
- owo-lib/owo-library
- fabric-language-kotlin
I'm aware these are unneccessarily complicated, I was just having fun recreating one of the favorite fantasy characters I've written :D