[Lord of Fire]

Originally Posted by LoweGear

I didn't say there was anything wrong with the name though, as Katyusha is a legitimate Russian name. it's just incredibly rare in anime.

I think it's more a reference to the "Katyusha" multiple rocket launchers that the Soviets first developed in WWII. That would tie in with all the WWII equipment we've seen in the show up till now.