Stalinvast

Stalinvast is a Segmentum Tempestus hive world from Ian Watson's Inquisitor, the Hydra-and-genestealer stage Inquisitor Jaq Draco walked into and the Imperium later wrote off. This pin is that early-BL catastrophe, not a random Stalin-namesake factory.

Cults, Inquisitorial knives, and a planetary end that later sources treat as Exterminatus-adjacent leftover all sit on this crust. Stalinvast became a dead-world rumour with a hive-world past. It is not Necromunda and not a later Ciaphas Cain joke planet.

Stalinvast still matters as one of the oldest named hives 40k fiction ever burned. Unofficial fan summaries keep the Tempestus parent and do not relocate the pin to Obscurus or file it as a living tithe world.