I had an idea for a weird mechanicus world, if anyone would like to share their opinions.
I’m thinking of a system colonized by a small Mechanicum facility in 30k but during the Heresy had a large imperial troop transport crash before a warp storm isolated the system for 10,000 years.
What emerged was a forgeworld where the imperial and mechanicus cults have merged entirely with the Emperor fully realized as divine Omnissiah, rad scoured hives and a very professional skitarii as the normal troop tithe. More human than a normal forgeworld but far more mechanicus than any imperial world.
Ecclesiarchy and hardline mechanicus hate them for obvious reasons but their treacherous and isolated position plus their good productivity keeps them from facing any real reprisals.