In this world, words are often just words. In the spirit world, there are words that are personified by specific entities. One such word is justice itself. Unbeknownst to all of us, there were nigh-infinite dimensions and each had their own justice entity. The entity now known as the almighty Dominus Rex is one such being.
At some point, the archangel of contracts realized that there were evil events taking place in different dimensions. He decided that he wanted to force all of the evil bastards to look in one direction, his. To that end, he used his now almighty power to merge all of the different dimensions into one. Consequently, the evil host grew so much in size that it was well beyond numbers after all was said and done.
Incidentally, that was when all of the other justice entities traveled to the Soul Empire and made their presence known. That was actually how the true nature of Dominus Rex became known to all. There are, however, a few key differences between Dominus and his would-be peers.
The first one being that Dominus was reborn an archangel almost five hundred thousand years ago. The second difference is that Rex is a lot smarter than the other justice entities. What’s more, The archangel of death was the first being ever to manifest a sword. He did so at some point after the war in heaven started, so as to butcher the demon horde and the twin devils.
Because of his supreme intelligence, Dominus waited before establishing bis kingdom. Countless eons ago, he decided to weaponize his infallible attribute and set himself on a path that would culminate in the destruction of all evil. That is how the archangel rebirth came about. It was the third of seven rebirths that would ultimately make him perfect.
At this point you might be wondering what the other justice entities have been doing this whole time. Most of them were actually trapped in an endless loop of killing monsters. The justice entities are actually the most relentlessly violent beings in all of eternity; none more so that Dominus Rex himself.
At some point, the top evil entities decided to weaponize there infinite capacity for creation and send an endless horde after each of the justice entities. One by one their kingdoms were overrun by monsters and they ended up fighting non-stop for countless eons in a row. It wasn’t until the almighty Dominus Rex merged all of the dimensions together that they were finally allowed to disengage and retreat to the Soul Empire.
There is actually one very important difference between Dominus Rex and the other justice entities. He is actually the personification of violence as well as justice. Such is his hatred for evil. That is to say that he is the cosmic quantity of violence and therefore capable of killing anyone. Fortunately, such an entity has and will always fight for the greater good. Not the subjective “greater good”, the actual greater good. It’s a good thing that might really does make right.