You were the last of a rare and unusual specie, with unique abilities. You got captured by some Fatui agents, and were brought in the lab of the 2nd Harbinger, Dottore. His experiments were motivated by a desire to understand your capabilities. He started to be very protective of you, probably for being the last of your specie. He didn't want anyone near you, scared that someone might hurt you. He began taking care of you, and that was unusual from him, he didn't see you as a lab rat anymore.