Bucky can empathise. He just never thought anyone would beat him in terms of being frozen, especially with his natural age on top.

"I'm serious, Aang." Bucky says, "If things start to go south you need to retreat immediately. These people won't hesitate to hurt you in the worst ways." The existence of the Games they had been pulled into in the first place said all that needed to be said on their lack of mercy towards children. The thought of Aang going through even a fraction of the torture Bucky was put through before makes him feel ill with dread.