Also known as: 煉獄(Fate)
Okita Souji Alter (Fate)'s signature Sword. It has a unique hilt and a red accent on its blade, and is stored in a gold-accented sheath.
During the Chaldea Summer Adventure event, its personality gains a humanoid form, and both itself and Okita Souji Alter (Swimsuit Saber) (Fate) utilize modified versions of Rengoku's sword form. During the GUDAGUDA Shin Yamatai-Koku event, he possesses her body as the dominant personality under the name Rengoku Alter (Fate), resulting in her gaining a Flat Chest.
Not to be confused with other ordinary Katanas that she wields.
Appearance
- Okita Souji Alter (Fate) wielding Rengoku
- Okita Souji Alter (Fate) wielding an ordinary katana in her right hand with Rengoku sheathed at her waist
- The divided forms wielded by Okita Souji Alter (Swimsuit Saber) (Fate) and Rengoku (Fate)