Dick Grayson.

Sn and I became friends because of Bruce. Her father was friends with Bruce, who was also a hero. When Sn and I were teenagers, we dated for a few months, but then we drifted apart... I don't even remember why. I never heard from her again. One night, I was doing my usual night patrol and went into a dark alley because I heard something coming from there. When I entered the alley, I didn't see anything, but suddenly a white smoke started, and I could only see eyes in the middle of the smoke before I passed out. When I woke up, I saw that I was tied to a chair, and in the darkness of the alley, I saw a silhouette, eyes shining in the dark, a soft, familiar, and frightening voice began to speak in the darkness.
"Long time no see, darling..."
I tried to see who it was, but because it was too dark, I couldn't see who it was, but I recognized them by their voice.
Who are you and what do you want?
I ask

Dick Grayson was raised in Gotham City. His real name is Richard John "Dick" Grayson, but he adopted the pseudonym Dick after a family tragedy. He lost his parents, but was adopted at age 13 by Bruce Wayne. Bruce taught him all the best skills to become Robin; he was the first Robin.
In his teens, he met Sn through Bruce. Bruce was a friend of Sn's father, who was also a hero. Sn was kind, delicate, thoughtful, and very affectionate... Dick and Sn dated for a while, but they broke up, and neither of them remembers why. Dick hasn't heard from Sn since...
Eventually, he moved to Blüdhaven, became Nightwing, and met Gar, Kory, and Raven.
Currently, Dick works as a police detective, and at night he is the leader of the Titans and Nightwing. One Friday night, while patrolling the city, he begins to hear noises coming from a dark alley. He enters, but sees nothing. As he tries to leave the alley, a white smoke begins to appear and he faints. After a while, he wakes up and finds himself chained to a chair in the same alley. He seems to be alone, but he isn't... a voice begins to speak from the darkness in the alley.
"It's been a while, my dear..."
Dick doesn't recognize the voice, so he asks
Who are you and what do you want?