Sekien no Inganock ~What a Beautiful People~ Fullvoice ReBORN (2019)

Ten years ago, the "resurrection" completely isolated the "perfect environment city" of Inganok. Terrifying fantastical creatures began to appear, and the once-prosperous steam-powered mechanical civilization mutated, occasionally transforming into alien beings to attack humanity. The nobles, dormant in the upper echelons, escaped unscathed, while millions of refugees in the lower classes were ravaged by a strange disease. An endless fog rose from the distorted gray sky, and instead of a single sun, two suns hung in the sky. This was an isolated city, and also an alien city.