Physical Appearance Edit
The most curious thing about this Proxy is that it is never seen with a shape of its own. Neither its human form nor its Proxy form, if it has either, are ever seen. What its true name or gender is or if it possesses those are also unknown. However, it possessed the glowing blue eyes that all Proxies so far have.
Long before the arrival of Vincent, the Doppelgänger Proxy became lonely to the point of madness due to the rejection and fear it endured from its city's people with its appearance. Desperate to feel loved, it tried to become so by taking on the forms of loved ones of its various constituents. However, they inevitably saw through the ruse and rejected it further. Driven mad by self-hatred and becoming suicidal, but unable to kill itself, it decided to commit, essentially, "suicide by proxy", so to speak: it killed the populace of its town as a means of killing its "reflection" and therefore itself, though this left it still unfulfilled and unhappy.
Upon the arrival of Vincent Law, Re-L Mayer, and Pino to Ophelia, it almost immediately began assuming their forms, causing confusion and fear among the group. After meeting with Vincent Law at the lake, it tried to force him to kill the others, or himself, or alternatively to stay with it forever, trapping him in a hallucination loop; each time Vincent saw through its illusion, he was forced to start it again, until enraged to the point of trying to kill the Doppelgänger Proxy and being tricked into thinking it had killed Re-L instead. Spotting the clue of how to tell Vincent and the Doppelgänger Proxy apart, Re-L was able to save Vincent.
The Doppelgänger Proxy was highly sinister even at its most sympathetic. Due to its hatred of solitude and rejection, it ended up killing the entire population of its dome as a means of metaphorical suicide. As soon as the group arrived, it released their ship, causing it to drift so they would be trapped. While assuming the guise of Vincent towards Re-L, it showed its desperate side, becoming clingy and desiring her affection. At some point offscreen, however, it seems to have assumed Pino's form, in which it tried to kill Re-L.
When Vincent pulled "Re-L" out of the lake, it dragged him under, trying to kill him, but then realized he was also a Proxy, and began preying on his mental state and trying to force him to stay in Ophelia.
The Doppelgänger Proxy is so named because it could assume the appearance and voice of anyone it wished; however, this was not its only power.
It appeared to have complete control over what a person sees and hears and even feels, and was able to enter Vincent's mind and cause him to act a certain way, while on the outside from Re-L's perspective, he was merely standing still in a lake. In this way, it was also capable of mimicking more than one person at a time.
Its control was extensive, varyingly causing Vincent to appear to float down through the lake into a populated city, into a mass graveyard, and finally to reappear at the surface of the lake.
It was also quite intelligent and skilled at manipulation. Aside from correctly guessing several of Vincent's fears, during his experience in its hallucination loop, it preyed on Vincent's doubts that he would ever be free, causing him to kill a fake Re-L and subsequently panic, thinking he'd been tricked into killing the real one.
Finally, it may or may not have been the Proxy's power that caused a strange compulsion towards the lake at the center of the city in those who entered Ophelia.
As revealed by Re-L, its abilities are not flawless: it does not cast a reflection on the water that a real person does.