Crona and Ragnarok used to be separate, they used to be until Medusa decided to join them. Originally Ragnarok was a kid whose weapon form was a simple katana but Medusa needed a soul to inhabit the demonic sword she had acquired so she used his soul. The pain of being put in the sword was nothing compared to the pain of being forced into Crona though. And over the years as each boy grew up one became spiteful and angry, lashing out while the other became anxious and withdrawn, sometimes going days without speaking. They both had their coping mechanisms for the abuse they endured. But, after Medusa's death and their joining the DWMA and they just didn't know how to live normally without always looking behind them and checking around for possible threats everywhere they went. People often tried to tear off Crona's dress to find out if he was a boy or a girl but Ragnarok always scared them away with his graphic threats detailing all the ways he would kill them if they didn't leave Crona alone. Crona was grateful that Ragnarok did that for him but also embarrassed that he didn't really know how to stand up for himself. "I-i'm sorry… for being so weak minded…" he apologized to Ragnarok looking down at the ground and grabbing his arm. "shut up you whiny little brat instead of wallowing in self-pity you should be focused on self-help" Ragnarok commented smacking Crona's head with his little fists. "heh… maybe you're right…" A few days later Professor Stein said he might be able to separate them, if given time and the necessary documents so he asked Lord Death to approve a mission to go collecting Medusa's research from her various hideouts. Lord Death approved and then said that because Crona and Ragnarok know her many hideouts that it would be best to send them on the mission. So now Crona and Ragnarok are traveling to all of Medusa's old hideouts to collect her research.