I thought it might prove helpful for some who do not know BlackJack Landar well, how his mind and emotions work. Some will read his profile, which states he is a hired killer and immediately think he has no emotions and forms no ties to anyone. That is an unfortunate assumption. BlackJack is a man who does care about some, I repeat, some people. But those people either have to be related to him by blood or have earned his respect.
Now Black is a ruthless killer. When he takes an assignment, he see's it to completion without any undue emotion. The target (person who is to be murdered), is simply that. A target, the job to be done. Black does not take pleasure in killing as some do. In all of his business dealings, whether legitimate or not, he strives to keep emotion out of the equation. To him, emotions and business is illogical and just plain bad business practice.
In Deadwood there are a few people he actually cares for. First is Dio Kuhr, or Miss Dio, as Black always refers to her as. He found in her a woman of strength and ability. He learned of some of her past and his respect for her increased. She had once requested that he not harm anyone whom she cared about. Out of his respect and growing fondness for her he agreed. This did not sit well with Black's employer at the time, but that is a story for another time.
The other two people that Black cares for in Deadwood are Clay Kungler and Daisy Stratton. Black considers Clay to be a kindred spirit, due to Clay's habit of collecting the heads of those he kills. Black is puzzled as to why Clay collects these trophies, but figures it does no harm and perhaps some good. Daisy, who works as a prostitute for Clay. Daisy reminds Black of a girl he had known in his youth. Because of this and that she is connected to Clay, Black has set himself up as a sort of protector. He almost see's her as a sister, though not quite that. Even Black has trouble explaining to himself the relationship between him and Daisy. What he does know is that the man that brings harm to her will pay in blood.
So, as you can see, Black is not some emotionless killing machine. He does have relationships and feelings. I would advise those who meet him to treat him with the same politeness and respect that he shows everyone. Those who become rude to him may well not live to regret it.