Yeah, he is really strange person... But there's no need to give him too much attention. Yeah, it's good to warn players, so they would know what to expect, but talking to him is meaningless. I tried to do that long ago, and got harassed ever since (~1 month full of various messages of threatening, spamming, etc), but ignorance beats his ego. Just absolutely ignore and you would be fine. However playing with him or against him is tough (especially with him on team).
Moreover. Yesterday, after playing with you, Pacov, I played a game of 3v3 when your_maker was on enemy side. Of course his allies got harassed for every death they got and thus forced one of his teammates to leave the game. After that, he started pm'ing me to leave the match, because it's not equal. He was doing this for some time and then started to scream in game chat the same thing "Dark, leave the match!" or something similar. I didn't and got blamed again for playing on stacked teams 
To your_maker. Yeah, I play on stacked teams as much as I can and would be willing to beat you next time 
Edit: Pacov, don't listen to what he says. It looks like as if you need to put arguments that you don't play on stacked teams, etc. You know yourself and other people also that it's not true. As of now I probably didn't see a single time when you would try on purpose to make your team stronger 
P.S. Interesting argument of your_maker that playing with me = stacking teams. So this same argument for me would be equal to - me always stacking teams 