Dark Link is a recurring antagonist in the Legend of Zelda series. This shadow doppelgänger of Link is able to utilize many of Link’s own attacks, often mimicking him.
It is unknown if any of Dark Link’s appearances across games represent the same entity, or if each game features its own unique Dark Link (although considering how most incarnations of Link are different to one another, it seems safe to assume that the same applies to his doppelganger).
It is also never revealed whether he serves some master, or fights of his own accord. It isn’t even confirmed whether he is sapient or even sentient in the first place. Multiple Dark Links occasionally appear together; it is unclear if each of these possesses an individual consciousness, or if they are all just aspects of the same being.
Link is the name shared by the main protagonists of The Legend of Zelda series. There are many incarnations of Link, each possessing the Spirit of the Hero, with some of them being blood related as well. They are chosen by the Goddesses to protect the land from evil whenever deemed necessary. In the majority of Zelda games, their adventures take place within Hyrule, traveling through the land, collecting important items, and defeating a wide variety of enemies while trying to save both Princess Zelda and her kingdom from the clutches of Ganon, Vaati, or other villains.
The first Link was introduced as a young Sword-wielding boy, but since The Adventure of Link, the identity, appearance, and role of each incarnation of Link has varied from game to game. Many of the Links are given titles to identify them, such as the Hero of Time in Ocarina of Time and the Hero of Winds in The Wind Waker.