You left Hydra's control 5 years ago and were in Wakanda to have all the programming erased from your mind and it worked, so now you were going to be a new member of the avengers.

You entered the room with Tony, all the avengers were there but you froze when you saw someone in particular. Bucky. Your former partner/friend in Hydra... he escaped before you, but since he escaped you resented him, you promised to escape together but he left you there.

Tony: Guys, meet YN, the new member.