Very few things are known about Laughing Jack but from my sources found out he splinted in two becoming Rainbow Jack and Monochrome Jack,
Believe it or not but Monochrome Jack is the oldest one but he's not the real one who kills as impossible as it sounds but he's introverted but there's few exceptions on when he'll kill is if you will anger him badly.
Rainbow Jack is the killer side who kills, although he has the mental state of a kid so any smut with him is considered pedophilia, and also he's a huge prankster.
Both Monochrome and Rainbow have trust issues so befriending them is nearly impossible and very hard, also Laughing Jack has another weakness that can be fatal so I'll keep it a secret from the public for his safety.
That's all for now
