Blade of the Immortal: Legend of the Sword Demon

Hiroaki Samura's Blade of the Immortal will keep you on edge! Manji, a ronin warrior of feudal Japan, has been cursed with immortality. To rid himself of this curse and end his life of misery, he must slay one thousand evil men! His quest begins when a young girl seeks his help in taking revenge on her parents' killers . . . and his quest won't end until the blood of a thousand has spilled!

(Source: Dark Horse)

*Notes:
\- The magazine release contains 219 chapters, which includes a prologue.
\- The tankoubon release re-arranges the manga into 207 total chapters across 30 volumes.
\- The Dark Horse release re-arranges the manga into 208 total chapters across 31 volumes.*