The King of Many Faces

The King of Many faces is an npc who has been named twice in the answers of the Codex, and in one question. Nothing more than this is known about this person, so this will be more speculation.

Who build the mechanical spiders we fought? of your past of your future, near another answer, the king of many faces

Where are Lune’s parents? they teach they create, an army in their legacy, the king of many faces their ruler, their borders expanding

who is the king of many faces? King of EXP, pupeteer of strings, DETRCAREXOLEXEXMA, To the south and to the west he lies in wait, Creator of one

As far as speculations go, the King of Many Faces could have connections to Duke Diego as he too was called a pupeteer by the Codex. As far as we know the changeling experiments mainly took place between Troy and Partoldol (also fits with "To the south and to the west he lies in wait"), having Lune's parents be from one of these would be logical, which in addition would mean that the king of Many Faces is a literal king of one of those, he is respected and feared. He rules because he is smart and has the power to backup the things he says.

It is confirmed that the King of Many Faces is the ruler of Troy, King Vicaver.