Mayari is a Aasimar Conduit (Cleric-like class of the Sun domain in Draw Steel), in a wider Asia-inspired setting. She was born human, her aasimar nature manifested itself in childhood as golden marks evoking the sun on her skin, particularly around the eyes (though perhaps elsewhere too!). She was taken to a temple where she's revered for her connection to the Sun divinity and served as a shrine maiden/priestess until circumstances drove her away, forcing her to become a reluctant adventurer.
Being isolated from most people her own age and raised more as a religious figure than treated as a normal human being, she has poor social skills and comes off as quite cold and aloof. People perceive her as if she's annoyed with everyone all the time, but the truth is she just doesn't quite know how to interact with people despite yearning for a human (or otherwise) connection with someone who doesn't just see her as a a religious figure.
I'm not particularly strong at designing characters so I hope I've given enough inspiration/information. I would love if someone who's more skilled or more creative than me to bring her to life, but even if you're just reading this, thank you for your time!