That Time I Got Reincarnated as a Slime Episode 22 English Subbed

Rimuru, Ranga, and the students enter the Dwelling of Spirits and a spirit in the opening labyrinth battles them with a giant metal golem to test them, though Rimuru quickly incinerated it. The labyrinth spirit introduces herself as Ramiris, one of ten Demon Lords, though she’s so small no one believes her. She explains that Leon, who summoned Shizu, used to be a Hero before he fell from grace and become a Demon Lord. Likewise, she used to be the Queen of Spirits before dying and returning as a Demon Lord. In exchange for creating a new golem for her, Ramiris agrees to aid Rimuru in summoning superior spirits.