Clevatess: Majuu no Ou to Akago to Shikabane no Yuusha

It's an anime about an adventure with a female protagonist with a unique power system. Both have intriguing stories and simple characters that somehow have such depth that makes you want to know more! The world-building is very important to both anime. Overall, it's an adventure anime with a female protagonist, great characters, and amazing world-building 

They are both explorations of OPMC tropes and have similar vibes especially with the mix of hard violence and a dash of dark humor. They even have similar aesthetics, with that grimy dark fantasy look and the low res filtering. Clevatess could pretty much be an extended version of an episode of Ishura.  

Clevatess in many ways reminds me of Meruem, the main antagonist of Hunter X Hunter Season 5. Both are powerful beasts capable of one-shoting entire countries, but ultimately end up betting everything on a single child that shows them the better side of humanity. A journey in which they explore what humans are and the world is about. 

Both series have passionate MCs who are forced to work under a powerful being with the ability to almost entirely wipe out humanity at the drop of a hat. Both MCs struggle with the morality of the decisions they have to make while working with these powerful entities.