Omnus Compositae used to be human, until he got cast into the void because of the fucking Merchant.
He managed to get dragged into an anthro version of Equestria and does not go around seeking adventure, he is quite happy to stay where he is and start a life there, Thank you, but then he got a friend, who was pregnant with twins, that was lost in his forest, he took care of her until her husband came and found them, then went on with life.

But later that year he got a letter, coming from The Twins and their mother, asking him to come to the royal castle. Whereupon he got a private audience with the King of All Things Living, and killed him, sending everything into a spiral of devastation. to which he answered with.
"I Don't Know."
The Twins names are Luna and Celesta Princeps, The Princesses of Equestria.
The King was their father
Their Mother's name is Faust.
And Omnus is the lord of balance….
But that was all a thousand years ago.