It may be useful to know if the behavior done by both parties constitutes a violation of forum rules. I shall examine the situation based on rules 1, 2, 6, and 7.

There may be a rule violation of rule 1 in the b*tching thread, as people were complaining about another forum member. However, since the OP participated in those activities, it is less clear if the conversation is on-topic.
This is perhaps the rule violation with the most evidence on both sides. It is easy to to find some statements that may be considered as personal attacks on chyron, such as the post that Possessed made declaring that it was “fucking creepy” that chyron watched MLP. But there may well be foul play on both sides of the coin, as chyron made a very incendiary comment to Possessed calling him a “fucking retarded monkey.”
chyron repeatedly protested posts made about him by several forum members. This can be considered harassment.
This is mostly a repetition of rule 2. While chyron wasn’t being attacked based on race, religion, gender, etc…, he could still make a case that he was being personally attacked. Similarly, Possessed can say that this happened to him too.