mystery

looks: In both his demon and human forms, Mystery is depicted with his hair styled in a way to where it covers half his face. As a result, his mouth is the only visible facial feature of his.

His human forms shows him in a pink shirt and a blue vest with his hair being light blue.

His demon form depicts him in a black attire, his hair being more dark blue, and wearing a dark hat. His skin is more pale and covered in markings and has claws and fangs like the rest of the boys.
personality: Mystery seems to fashion himself as someone who is always shy and quiet, with many of his poses simulating embarrassment. He notably emotes the least of the Boys, likely due to his eyes being covered. This is all used by him to make his fans trust him.

What personality he does show depicts him as mischievous and sly like the rest of the Saja Boys, especially when it comes to taunting Huntrix. He is implied to be more aggressive than the other Saja Boys, seeing as during the Signing Event, he started barking incoherently at a fan when they talked to zoey