Mystogan

Mystogan is a mysterious, former S-Class Mage of the Fairy Tail guild in the anime Fairy Tail. He is known for his secretive nature, rarely showing his face or interacting much with other guild members—he often wears a mask or cloak and uses sleep magic to avoid being seen.

He is actually the Edolas counterpart (parallel world version) of Jellal Fernandes, sharing the same appearance: blue hair, dark eyes, and a distinctive red tattoo/marking on the right side of his face. His real name is Jellal, and he is the prince (later king) of Edolas.

Unlike Earth Land mages, he lacks innate magic power (as is normal for Edolas natives) and relies on special Magic Staves to cast powerful spells. He joined Fairy Tail to secretly oppose his father's plans involving the two worlds and eventually returns to Edolas to become its ruler.

He's generally portrayed as stoic, loyal (especially to the guild), and determined to protect both worlds.