Fear of guns?
He fucking hates to remember that that event happened. It hadn't been long since he was a Phoenix member, and until then, his tasks were considerably light, sneaking inside places to steal stuff or information. But, that night, he'd finally move on to something more important. He was excited to finally be trusted with more responsibility. Fun, right? Not really. He can still feel in his hands everything he did that night. The first time his existence would be acknowledged by someone. By two people. A man, a new member of Hydrus, and his daughter, a kid. A kid that Jaguar was pointing his gun at. That man wasn't even a bad person, Jongin knew that. He had joined the gang because he needed money, and the legal jobs he was able to be hired at wasn't enough for him and that little girl, who had been hidden to prevent exactly what was happening right at that moment. But the man was an easy target. His condition, unfortunately, was perfect to take advantage of. Jongin could clearly feel the child’s bones as he held her in place. And her father's desperation didn't help a newbie at holding hostages. God, the girl's frightened cry. He was a monster. I'm a monster. She'd have nightmares about this one night and it'd be because of him. He wanted to get this over as soon as possible, but the man couldn't even talk properly as he was interrogated. Jongin was glad his face was almost entirely covered, as he was in pain too. And scared. The gun he held scared the shit out of him. It was his first time actually using it outside of training, and it was loaded. And ready to shoot, his finger right at the trigger. Which he almost pulled by mistake when the girl did an unexpected movement, but with fast reflexes, Jongin didn't let her go and his earlier trembling finger didn't move. It wasn't moving at all. Steady. He could do that. He was in charge of everything that happened inside that room.
And he did what he had to do, collecting the new information he needed and leaving both unharmed. Physically, that is. Til the current days, this was one of the most traumatic experiences of his life, but at the same time, quite eye opening. It hurts, but he treats that as a learning event: to not be afraid of what he has to do. A few days after, he went past the humble house, but it was for sale. Had they actually moved, or did Hydrus find out about his confession? Jongin hopes that they're safe and the first hypothesis is the right one, but, at the same time, he knows the nasty place he lives in. Would he like to move away too? Probably.