It genuinely pains me that someone can be so mentally handicapped to flame someone for no reason...
I'm surprised you don't see the irony in complaining about flamers and in the same breath spouting hate speech and branding them as "mentally handicapped".
Seriously, you're proving no better than them here. I get that flamers suck, but you're going well over the line with your complaint.
...I genuinely do not understand what goes on in the mind of these poor people, just what? if anything...
Again; implying that nothing goes through their head and that they're just mindless vitriol machines makes you no better than the flamers. They're people. Just because you don't readily understand them doesn't mean you have free reign to insult and dehumanize them over the fact that they flame.
Not even the insults themself give me pain, just the fact that someone flames another human being for no reason.
For seemingly no reason. It's not that they have no reason, it's that their reasons for flaming are poorly conceived or counterintuitive.
JuSt MuTe HiM oR HeR!!!!!!!!!!1!!!!, no.. it's running away from the actual problem that these kinds of people have.
Frankly? It's not your problem. It's theirs. You're not playing League to counsel wayward toxic players into being better sports. You're playing League to play League. If someone flames you, you're supposed to mute them, report them, and move on.
Mute them so that you don't have to deal with their flaming in the match, report them so that they can suffer repercussions for their misbehavior - and consequently, be put on the first step to seeing and fixing the problems with their behavior - and move on, because the odds of you meeting that particular player again are comically low.
And of course; Focus on yourself, not others. You're not going to be able to "fix" a toxic player in any match you play. If they're toxic, they're unreasonable, and no amount of trying to engage them will actually help assuage the problem. You should focus on your play, and, more importantly, your problems, as I pointed out earlier, above everything else, because you are the only person you can control.
League is a mentally painful game.
Well, what can I say? You vehemently refuse to mute problem players, making the game mentally painful in so doing. If you don't want to use the tools at your disposal to make the game less stressful, there's nothing that anyone here could say that would really help you.