Black Scythe is a two-handed level 65 Attack weapon. It can be made by fixing a B. Black Scythe using 5 Blue Balls at level 55 Crafting.
Making a Black Scythe
The B. Black Scythe is a rare random reward from the blue chest in the house in Rockwort Village that requires Blue Keys dropped by Blue Chests in the Magic Cave to open. Blue Balls are made by combining 500 Blue Shards at level 55 Alchemy.