That Time I Got Reincarnated as a Slime: Trinity in Tempest (Manga) 6

As players of Monster Hunter and Dungeons & Dragons know, the slime is not exactly the king of the fantasy monsters. So when a 37-year-old Tokyo salaryman dies and wakes up in a world of elves and magic, he's a little disappointed to find he's become a blind, boneless slime monster.

REVENGE SERVED COLD

The hostile human nation of Falmuth staged a devastating attack on Tempest, the peaceful land of monsters. Now, in order to bring back the dead and protect the living, Rimuru is determined to become the most feared of beings: a Demon Lord. But this evolution comes at a terrible price, and the assailing humans will soon realize how poorly they've chosen their enemy...