Tensei shitara Slime Datta Ken 2nd Season - episode 11 - 22 Mar, 2021

Rimuru managed to sacrifice 10,000 souls from the Falmuth kingdom as a condition for his evolution into the True Demon Lord. When he was about to do evolution, Rimuru summoned a demon which he later named Diablo and later became one of his loyal followers. During the period of Evolution, Rimuru and all the inhabitants of Tempest fell asleep so that the city was guarded by Diablo and the Yurazania army. (Sumber: Crunchyroll)