Chapter 39: The Otherworld Adventurer and the Secret Weapon

Saikin Haitta Shiro Madoushi ga Party Crusher de, Ore no Isekai Boukensha Seikatsu ga Houkai no Kiki na Ken ni Tsuite

This chapter is listed on MangaDex, but the readable pages are not available through the internal reader. It is only available through the official publisher link.