Proceed at your own risk.
Brio (formerly known as Ezael Stormblood, High Retainer of the Noble Nightcrest Family) is a Dusk Elf with silvery hair and potent combat abilities. He has purple eyes, because he has been enchanted by Herobrine. The enchanting was done through a Rune Chamber. He made his first appearance in Diary of an 8-bit Warrior book 2 (From Seeds to Swords), and is now a close side character.
During his time in Ioae, the Dusk Elf island kingdom, he served as the high retainer to the Nightcrest family. The King of Ioae had requested them to learn ancient knowledge. This drew the attention of Herobrine, and he invaded Ioae to prevent this from ever happening, seeing this knowledge as a threat. Ezael managed to save young Alyss (Breeze) from the Eyeless One's invasion, swearing to her mother that he would protect her. Ezael then brought her to a place of refuge, where they met many other Dusk Elves.
Here, they would create a new life away from the tyranny of Herobrine. And so the Dusk Elves created their city of Shadowbrook. Breeze grew up in this place, with Brio watching over her. However, they were discovered once again, and Shadowbrook was invaded and destroyed by Nethermancers sent by Herobrine. Everyone in the city was killed, save for Brio and Breeze. They were captured and painfully empowered through rune magic, advancing their physical capabilities greatly. Eventually, the two were able to escape their hated prison, where they fled to the east.
Herobrine sent his minions to find them. In Diary of an 8-Bit Warrior: Forging Destiny, Breeze describes a ghost, slowly emerging from a wall. She also describes a pigman that chased them with a dagger imbued with Wither XII, with a durability of one.
Finally, after days of stumbling through eastern Ardenvell, they finally came across Villagetown. Deciding that concealing their identities would be prudent, they disguised themselves as villagers through the use of potions, and entered the city, where they were not given too much attention. In this time, Brio became close to the Mayor, advising him and even stepping up to take his place in the brief time the Mayor was out of commission. He also became an Elder.
In his Highborn disguise, Brio looks the typical male villager, with a bald head, straight black unibrow, light brown skin, and a large nose. However, his true Dusk Elf form is shown to have slightly paler skin than his villager disguise. He has a small nose, whitish-gray hair, a more slender facial structure, and elven ears. His eyebrows are noticeably longer than a human's. Interestingly, both of his alternate forms retain his purple eyes, a side effect of Herobrine's experiments.
Brio was first seen wearing black clothing, and has continued to do so throughout the books, as black was the main color of Shadowbrook, due to the sorrow they all faced.
Brio's first appearance portrayed him as a mysterious, enigmatic character. He wore sunglasses and a dark robe, escorting Runt to their interrogation room. He had heard of Runt's Rocket Potion, and was very curious of this, questioning him extensively on his new potion. Brio eventually managed to re-create the recipe, rewarding Runt for his discovery. However, he had his suspicions as to whether or not Runt was harboring a monster. His aura of mystery was only increased after Runt saw he had become the school's new headmaster. He is a strict taskmaster, as seen by his changes to their school. But after he reveals himself to be Breeze's guardian, he begins to more openly show his affection for her.
Due to Herobrine's experimentations, Brio is incredibly prowessed in combat. He single handedly drove the mobs back from the town square, which, at the time, was overrun by zombies. It is hinted that he is even stronger than Breeze from Runt's remark: "Where Breeze's eyes remind you of a low-level enchant, Brio's eyes are more like that of an enderman."
When Breeze and Brio escaped the isle of Ioae, they took several artifacts prized by the Nightcrest family. Eventide and Morningtide were kept by Breeze, until the day they could be repaired. Brio now possesses a Keystone and his tome, which contains every Advanced crafting recipe and almost every Legendary one, along with likely many more rare and powerful items.