Who they are: The Hand, a.k.a. The Yami No Te
Their powers: Each member of the Hand is an extensively trained ninja warrior, proficient in weapons, hand-to-hand combat, and stealth. They also have the ability to mask the sound of their heartbeats by lowering them significantly.
Their story: The Hand is an ancient warrior clan of ninja, trained in martial arts and other physical skills. Much is still unknown about them, other than they have been led by master assassin Nobu Yoshioka and taught to await the arrival of a being known as Black Sky. They have infiltrated New York City as part of the search for Black Sky, and have dug a massive tunnel straight down into the Earth. Though it is still unexplained, they have also developed the power to bring people back from the dead, including Nobu himself.
Where will we see them next? Unknown, but it’s likely their involvement with Daredevil is far from over.