source- https://www.dlsite.com/maniax/circle/profile/=/maker_id/RG14831.html
Artist- https://www.pixiv.net/en/users/29088547/artworks

premise- The Kappa Swordsmanship, a martial art passed down through generations of the Kappa tribe,
has a promotion test that requires defeating three opponents of the same rank.
Those who lose the match face a harsh fate: their demonic energy is drained into a tentacle bath beneath the arena.
Can Mizuna, the swordsmanship girl challenging for promotion, continue fighting while sending her fellow disciples to the abyss...?
*Battle between naked and loincloth-clad women & ryona (no blood, but depictions of wounds and mild dissolution)
Tentacle attack (all characters are attacked)
28 pages of manga, monochrome
Includes textless version

1-30 text
31-59 textless