Darkness emerges from the Konosuba series within a crossover narrative. She wields formidable physical strength but suffers from poor accuracy as a swordswoman, hindering her combat prowess.

A defining masochistic streak marks her personality; she openly relishes pain and humiliation, frequently voicing related fantasies without restraint.

Transported to another world via a wormhole, she becomes separated from the main group alongside Shalltear Bloodfallen, Aura Bella Fiora, Demiurge, Subaru Natsuki, Puck, Beatrice, Viktoriya Serebryakov, and Filo. The golem Pantagruel rescues them, delivering the group to a village where they reunite with other transported individuals.

When class groups divide, she serves on the gym committee with Cocytus and several subordinates of Tanya von Degurechaff. Interpersonally, she engages in a Valentine's Day discussion about chocolate gifts with Rem and Shalltear, carefully avoiding any direct admission of intending to give chocolate to Kazuma Satou.

Confronting the threat of out-of-control golems, she contributes to a collective effort where characters from multiple series collaborate. Their strategy involves teleporting the large golems into a hole, enabling Megumin to destroy them using her Explosion magic.