These angels act as watcher and overseer of the world for the creator god, Watos. They are the ones behind all the tragedies on Earth - the extermination of a race and a new beginning. In seeking to create a perfect world, which they do in God's name, they had been destroying and re-creating a new Age. The Age of Gold, the Age of Silver, the Age of Bronze; respectively the Age of Dragons, the Age of Giants, the Age of Elves and now the Age of Iron or the Age of Humans - faced their wrath of seeking perfection. In the 14th episode, a mural depicting them is shown with Arawn's face is scratched with a sun on the whole lot of the Angels, symbolizing Watos. One of them, who is a senior looking man with brown hair is holding a wooden staff, hinting that he is their leader or an Archangel (it is possible that he is the one that first speak during a meeting in Lucifer episode and charge Myrddin to deal with the new Angel). Arthur comments that they look like the one that murdered his father and compared Arawn's similarity to them. It is possible that the Twelve Angels at least visited the elves in the past, given that the artist know how they looks like. And, Pwyll knows the name of Myrddin, showing that he knows the name of the Angels respectively as well, supporting the Angels' visit theory. And, Limwris also told that the fortress Avalon was constructed by the Angels and the elves worshipped Watos just like the Angels seem to support these theories. It is also possible that they betrayed the elves afterwards, as they began to rain their city, Avalon, with Gravitas-emitting Obelisks to exterminate them and Pwyll comments that the ``agreement with the heavens is as nothing.
It is possible they are based on Jesus Christ's Apostles. The murals in Arawn's tomb contain 13 figures, similar to The Last Supper painting. Furthermore, Arawn the 13th angel betrays them, similar to Judas Iscariot, the 13th person that Christ says will betray him. Myrddin's role is quite similar to Christ, as he sacrifes himself for the salvation of mankind.
Although the Angels worship Watos and strive to create the "Perfect World of Pure White" in His name, the Sun, which symbolizes Watos, never shines in the Heavens. It can thus be implied that for all their devotions, Watos does not listen to them anymore, having had enough of their hypocrisy.
They're the ones whom Arawn despises the most, calling them hypocrites who merely fear that the other creations of God would surpass them. Ogam harbours a strong hatred towards them for the near extinction of his kind, the dragons (with the exception of Myrddin, whom is shown to be his friend and even respects him. He also reprimanded Arawn for thinking his foster father, Myrddin, a fool in episode Lucifer). It is truly unknown what happened to the them after the death of Lector. However, should the Power of Words be addressed to Watos, it might be that the Angels fear taking action and becomes "tame" after judgement was passed on Lector (Merkadis was crippled by a Golden Light from Heaven called down by the Power of Words).
They use different disasters to annihilate species on Earth:
- Dragons-Dropping one of the two moons on them and thus creating massive impact that nearly wipe them out
- Giants-Sends megatsunami on their silver city. However, some survive and live in mountains afterwards.
- Elves-Raining Gravitas on their city to weaken and kill them.
- Humans-Covers their land with eternal winter and later ended through Myrddin's sacrifice that turns winter into spring.