The Dark Embodiments were created by the first Dark Embodiment, Rekka. Upon finally achieving his goal of fusing with his Nobody, Ignitas's Heartless became the very first Dark Embodiment, essentially becoming the pure darkside of Ignitas, Rekka. Rekka then proceeded to open a portal into the Realm of Darkness and, with his control over both the Nobodies and the Heartless, began ordering the Heartless to find their original bodies and possess them, ordering the Nobodies not to resist. This resulted in all the Heartless and Nobodies being no more, and only Dark Embodiments remaining. The Dark Embodiments physical appearance is not changed much, many of the weaker ones still looking like Nobodies, the only difference being they are no longer white and are now black. The more powerful Heartless and Nobodies however begin to reform into their old original being, the only difference being that they are now pure beings of darkness. Many of the stronger Dark Embodiments would later form the Malignant Shadow, an organization bent on sending the worlds into an everlasting darkness.
Dark Embodiments are the darksides of their original selves, with the same knowledge and memories of their original beings, just colder personalities and powers over darkness. They have the power and skill of both Nobodies and Heartless, and as such are twice as powerful as either of the two, and have much better and greater control over the darkness, as well as better intelligence as opposed to the Heartless. Because they are beings of pure darkness however, they, like the Heartless, must feed on light. More powerful Dark Embodiments often slay the weaker ones and steal the light they collected so that the stronger ones may devour it. Because Dark Embodiments are essentially the opposite of their former selves, they often find pleasure in tormenting those they once held dear, such as family or friends, and feel no regret in doing so. Darkness Embodiments typically have negative emotions such as hatred, jealousy, and rage. As a result many Dark Embodiments are physically and verbally aggressive, further adding to the dangerous threat they pose. Because the Nobody acts as the physical body for Dark Embodiments and the Heartless act as the soul, if a Dark Embodiment is slain then their old self is completely destroyed without a chance of reforming within Kingdom Hearts. This further adds to the dilemma of attempting to destroy them, as many find themselves unable to do so. All in all their overwhelming power, aggressive personality, and opponents reluctance to finish them off make the Dark Embodiments dangerous creatures that are very difficult to defeat. It should be noted that only Pureblood Heartless can become Dark Embodiments, as Emblem Heartless are created by technology, not from the darkness inside somebodies heart.