The point of origin for Aramasa is unknown. It was kept in Celica A. Mercury's Church for decades, eventually being gifted to Ragna once he had completed his training with Jubei. The blade is unique in that it is both a sword and a scythe, having a mechanism that allows it to swap between forms. The blade of the weapon is made out of metal and ceramic.  It has a large handle with a shaped pommel. Ragna used Aramasa in a reverse grip while fighting, and was noted to be very offensively oriented in battle. 
The weapon is currently missing, having been used for a makeshift grave for Ragna, but disappearing after Rachel Alucard and Izayoi visited it. 
- The name of this weapon is actually never properly stated in the games. It's name is revealed to be Aramasa through merchandise and official storyboards for BlazBlue: Cross Tag Battle.