Main Point: We are not barbarians - we need to treat each other properly (This applies to pm: See PM Policy).
We are all human and we all have feelings: this details proper treatment for both mods and players alike.
Each user is entitled to a certain level of respect. It is extremely understandable that, while playing NC or using the wiki, you will begin to aquire a list of people you really like to talk to and those that you don't get along with. However, while this is understood, re-read the first line of this sub-section.
Every user (Whether they are a chat mod or not) should respect the other users and, in turn, receive respect. You should not go out of your way to flame another person/attack them (Whether it's in-chat or not).
This applies to all situations - even if a chat mod has blocked you recently, it does not give you the go-ahead to flame them as soon as you are unbanned. In fact, doing so may just result in another chat kick/wiki ban.
If a mod has to solve your problem because you and another user just can't stop arguing/flaming each other on the chat or on other parts of the wiki, it will most likely be solved via kicking/banning. In short, try not to let it get to this point.
It is best that you take the user to pm/post on their talk page. If you can't agree to act peacefully towards each other, at least agree to stop interacting with each other in any way.