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Dark Link (ダークオブリンク, Dāku obu Rinku?, lit. "Dark of Link") is a technique that appears in Kingdom Hearts Birth by Sleep. It allows the user to shoot a giant beam of radiation. It is the opposite of Vanitas's Dark Cannon attack.
Dark Link is a class A Shotlock that has a max lock of 20 and deals dark damage. If Vanitas uses Dark Cannon or Dark Spiral at the same time as this Shotlock is used, a clash will initiate between Vanitas and the user, which can be won by rapidly tapping ( in Japan).
Learning Dark Link
Kingdom Hearts Birth by Sleep