Tensei Shitara Slime Datta Ken (WN) - Chapter 409

Reborn as Red Army Misha!

- Description from novelbuddy

Amidst a disaster, an orphan contracts a sickness.

Thirty thousand years ago, the Heaven Fighting Race who called themselves “Gods” invaded the Spirit Realm. Hundreds of races rose up in resistance, but ultimately suffered a crushing defeat. The Human Race was the first to concede, and the rest of the Hundred Races soon followed in succession.

Humans are clever in tens of thousands of ways, Gu are the true refined essences of Heaven and Earth.