Requests, Natasha X female reader
Reader is an alien (she looks human)her species exclusively Have things called alpha,beta and omegas. She is an alpha, her planet was attacked and she was the only survivor. She lands on earth and is captured by SHEILD, Natasha is sent to interrogate her, but when she smells and sees Natasha she goes crazy as Natasha is her mate. Her alpha instincts take control and she tries to escape to get to her mate while calling out with roars and growls, since she can't speak English (Since Natasha is human she doesn't feel the mate bond)
Reader is captured by SHEILD, after killing and displaying the bodies in public or what seems to SHEILD to be innocent people working for SHEILD, police etc. But the people reader killed weren't innocent they were hydra agents, and she is killing them because she was in the red room and was secretly in love with Natasha, but they made her think she had killed Natasha to break her. When Natasha is sent to interrogate her she thinks shield is trying to break her and she attacks Natasha only stopping when Natasha reveals the secret that Natasha had asked her to take her virginty as she trusted reader and wanted it to be her instead of a man she would be sent to seduce.
Reader is a person of interest for SHEILD as they found footage of her killing a rapist after he tried to rape her and when she fought back, he shot her and the bullet shattered like glass, then she killed him. She is ininvulnerable and has super strength (like Superman levels strength) Natasha is sent to seduce her, but reader is such a gentleman that even when Natasha is wearing revealing clothes reader never let her eyes wander, they go on multiple dates and Natasha accidentally falls in love with reader.
Natasha is married to what seems to be a normal women, but secretly hydra had planted code words into her mind, that's allowed them control her like the winter soldier, and reader has no idea that hydra is controlling her.