Purgatory Kabuki

For reasons unknown, former samurai Imanoturugi is obsessed with leaving the afterlife. To die in battle is a samurai's greatest honor, yet he is determinted to claim 1,000 swords from the fallen warriors who now share his residence in the dark underworld. By these means alone this highly skilled blades master will be allowed admittance back into the living world. But to what end? Upon what stone purpose does he sharpen his edge?