WARNING THERE ARE A FEW SPOILERS
Sino was a Great Mage and created San Lorenzo sometime in the past.
Sino appears to be an elderly human, standing a few feet above average height. He has a clean trimmed white beard and wears a blue and gold mage hat. He is seen wearing a blue robe with a gold trim. He carries a thin wooden staff with a gold perched blue jewel, balanced on top. In “And, Having Writ, Moves On,” the top jewel was switched to the Arcanum.
According to Dulcinea, he was the creator of San Lorenzo. Uli goes on and states that he was also the archenemy of the Bloodwolf and at sometime in the past he banished him to the Netherworld. After that he created three magic spirits called Tulpas and a place known as The Realm of Shades.
At an unknown point in time, after defeating the Bloodwolf, Sino split himself into two halves; a good half, and an evil half. The good half became Artephius and settled down in San Lorenzo with no memory of who he truly was. Because of his fear that he'd be tempted to take away people's choice to do right and wrong, the bad half was locked away in the Forbidden Citadel. He also hid the Arcanum and created a Tulpa to protect it, another to help banish the Bloodwolf to the Realm Of Shades if he were to return, and a third to help rejoin Sino's two halves if he was ever needed again. Their names were Orange, Green, and White.
Although his true form is never depicted in the series, it is assumed that the real Sino was a kind and powerful wizard, compassionate enough to create the guarded place to protect the orphans and citizens that lived there.
Artephius is just one half of Sino, the good half. It is reavelaed sino split himself into a good half and a bad half and locked away the bad half in the Forbidden Citadel.
Sino's legacy is a main driving point of the series with his artifacts and creations playing a key role in the overarching plot.
He, at the end, ‘kicks’ Puss out of San Lorenzo because of his personality.
- Fartholomew disguised himself as Sino once.
- Sino split himself into two identities, one good, one evil.
- Artephius is the good half.
- The bad half was lock away in the forbidden Citadel.