Miclio is Slay’s friend and part of a Heavenly Tribe which is praised in the world of Zestiria. These individuals can only be seen by humans with high spiritual powers. Some of these humans who accept to become a vessel for them become Monks and are able to use the Heavenly Tribe’s special powers.
Miclio is described as being physically shorter than Slay, however his behavior is quite the opposite as he’s more mature and calm compared to Slay. Both Slay and Miclio have a long running complex friendship with a mixture of rivalry that we will see blossom throughout the game.