I know Gustav, I'm getting used to being wrong. 
If he's abused people in the forum in the past, then punish him for those abuses. But as Tom said, this case is about the 2 OOC msgs, not whatever happened in the past. If he's found "guilty", then by all meanslook at his record for determining his punishment, but not for deciding his guilt or innocence.
I know I'm late to the party, but... using your own emphasis, he managed to get off of
those [forum] abuses by being unmuted via the Magistrates case. I know we've traveled quite far from my original point, but the way I see it, the "legal" process has been disrupted
in his favor, not otherwise.
Another point of contention you hold is that Kai wrote his negative (currently an undisputed adjective) OOC messages about the other players' gameplay... Can that not be an insult? If I offer to tie your shoes for you, is it not an insult to your intelligence? It should say something that it was quite difficult for me not to use the word "insult" to describe those messages; I had to actively edit myself.
What makes Kai's messages (and thereby, defenses) harder to swallow is that there is no way to "win" BattleMaster. Essentially, by definition, you cannot be "good" nor "bad" at it. I'm even quite certain that's one of the major selling points of the game. Yes, you can win or lose battles or wars, but there are many IG, IC, non-insulting ways to remove someone who seems to be hurting your realm.
