A tingling sensation passed through Nanoha's loins as the magic cartridges activated themselves. For a second they merely glowed a soft gold. Then Hayate drew her hand back, and four jets of cold white flame ignited.
Nanoha screamed as the dildo drilled itself deeper into her. The rings binding the four cartridges together dissolved, allowing them to move rapidly apart, splitting the unevenly tapering purple shaft apart. The result was like a rocket-powered speculum, forcing the redhead's anus gaping wide in seconds. Nanoha's teeth ripped into the fabric of the pillow, her fingernails tore out chunks of stuffing, and her untouched cunt gushed like a broken dam all over Hayate's bed, leaving a massive puddle of sticky fluid between her knees.
Eventually, the cartridges ran themselves dry. Nanoha collapsed to her belly on the bed, now soaking with sweat and panting fitfully, squealing as cool air travelled up into her colon.
"How obscene," Hayate giggled. "I can see all the way up Nanoha-chan's asshole. I bet I could put my hand in there now..." And that she probably could, the redhead's anus was a good six inches wide thanks to the spread dildo holding it open. Bands had reformed to hold the four segments apart in a square, which also helped to keep Nanoha's anus spread wide.
"Buh," gargled Nanoha incoherently, face-down in a puddle of her own drool.