Juu - Ninpou Makai Tensei

Juu - Ninpou Makai Tensei (十 ~忍法魔界転生~ Jū ~Ninpō Makai Tensei~) is a Japanese manga series written by Fuutarou Yamada and illustrated by Masaki Segawa.

Plot
This is the latest story of the famous "Ninpo-cho" series of Yamada Fuutarou. It begins in 1638, during the Shimabara Rebellion, where a powerful swordsman who should have died is instead transformed by an arcane ritual into a demonic creature. As time passes, more swordsman facing death go through this transformation. What could these new, demonic swordsmen be planning?