Astrid used magic to transfer her father's cancer into Dr. Strange. She then invaded the home of the Ancient One and took him and his monks captive in order to drain their powers. Baron Mordo was also there and she and her father went home to Castle Mordo. 
Once Dr, Strange realized he had Mordo's cancer, he went to the Ancient One's monastery to find Mordo. Astrid sent a demon to subdue Strange and bring him to Castle Mordo. A weakened Strange tried to attack her, but she defeated him. She shot magical energy knives at him hoping to kill him, but they were blocked by her father.
Tricking his daughter into thinking he wanted to kill Strange himself, he transferred his cancer back into his own body to let Strange fight, Astrid. Dr. Strange teleported the monks away, and Astrid summoned demons to attack him. Once he was done fighting the demons, Astrid teleported Strange's friends Jessica and Amanda to her side. She threatened to kill them if Strange did not surrender, which he did. Baron Mordo sneaked up and stabbed Astrid in the back with a magic knife which put her in a coma. He then cast her body into another dimension, so she could never hurt anyone again.
Powers and Abilities
Normal human female
Astrid is a product of incest. Her mother Lilia is the half-niece of her father Baron Mordo.