The Chosen One gets this title by joining one of the four mafia families in New Reno and having an Intelligence above 4. For each mafia family there is a chain of quests, upon the completion special ones they can become a Made Man of that family, even as a female character.
Turning against the family will cause your Made Man status to be removed.
For each family boss, there's a way to assassinate them without getting blamed for it, and killing a boss "silently" or in these special ways will not remove the Made Man title.
It's possible to become a member of almost all mafia families, by not becoming the Salvatores' Made Man until the quest from Mordino to kill Salvatore has started.
If a family quest is active when a family has turned hostile, the quest will be set to failed in the quest list.
Although the in-game description says "you look great in a fedora", no wearable fedoras are present in the game, and they are only seen worn by casino bouncers.
The sentence for paralyzing Jagged Jimmy J is not a typical sentence (normally poorly constructed and difficult to understand) said by low-intelligence characters, instead looking more like something that an intelligent one could say.