Cloak and Dagger (Marvel)

Cloak and Dagger are a pair of young superheroes, one controlling darkness and the other controlling light, whose complementary powers help cover each other's weaknesses. They are characters in the Marvel Comics Universe.

Ultimate Spider-Man
Dagger was among the wave of rising young heroes S.H.I.E.L.D was looking to recruit, however they had no intent with Cloak due to his temperamental attitude. However, Cloak fell into control by the demon Dormammu, who used him to kidnap various mystics and brainwash them to help create a portal for his army to invade Earth. After Cloak kidnaps Iron Fist, Dagger joins with Spider-Man to find him. They are able to discover Dormammu as the culprit and follow him to his Dark Dimension via Doctor Strange's Eye of Agamotto but confront Cloak as resistance from further passing. Spider-Man is able to bring Cloak back using Dagger's light daggers to exonerate Domammu's influence. The three encounter the brainwashed White Tiger, Iron Fist, and Doctor Strange and are forced to fight them; Dagger aids in breaking the spell over them with her powers. But before she can free Doctor Strange, Dormammu arrives and attacks them, forcing them on the retreat. Fortunately, Cloak uses his powers to help Dagger get close enough and frees Doctor Strange, who then helps the group escape the castle with Dormammu on their trail. Cloak offers to get everyone safely back to Earth despite Dagger's worry, but when everyone escapes through, he is halted from teleporting himself by Dormammu, causing him to become trapped between two dimensions and allowing Dormammu acccess. Spider-Man dons the Eye of Agamotto once more to temporarily incapacitate the demon while Doctor Strange banishes Dormammu back to his dimension. Spider-Man offers the two to join S.H.I.E.L.D., although the two state they will consider it. After departing, they are revealed to be working for Taskmaster who took them in and gave them shelter beforehand, and makes them turn against the notion of joining S.H.I.E.L.D.