Pov of a cultist:
I came back two days later carrying a metal casket, luckily they managed to create Kimera very quickly, but I made sure I followed through to make sure every step was being taken seriously.
I didn't see who the Black Market Alchemist was since he was wearing a mask, but his assistants were all slaves with purple Runes all over their bodies, clearly under a powerful curse engraved on their bodies by these Runes.
The process was something I had seen before, they used a child who was a slave, just as the Lord of Shadows requested this child had Pure Affinity with the Shadow element and high Affinity with magic, unfortunately, they did not find a boy, but as the gender did not it was on the Shadow Lord's roster requirements, so it should suit any gender.