thats just how i talk man...
Even in public? D'you go around restaurants and grocery stores telling people to kill themselves, throwing around hate speech?
'Cause, if that's how you talk, then I'm going to tell you flat-out; find a better way to talk.
...i mean freedom of speech?
As others have said, freedom of speech does not apply here. Riot isn't a government body, so your right to free speech isn't being infringed upon. You're still fully allowed to speak freely, but the 14-day ban is Riot expressing their freedom to apply repercussions for your use of hate speech and encouraging self-harm in their private space.
Here's a snippet from the Terms of Use, Code of Conduct - AKA, the rules that you agreed to follow, and which Riot can enforce at their discretion;
The following are examples of behavior that warrant disciplinary measures:
v. Transmitting or communicating any content which, in the sole and exclusive discretion of Riot Games, is deemed offensive, including language that is unlawful, harmful, threatening, abusive, harassing, defamatory, vulgar, obscene, sexually explicit, or racially, ethically, or otherwise objectionable;
I italicized the parts that I think apply most here.
Hate speech, of course, is harmful, abusive, and objectionable, and encouraging self-harm I'm 90% sure is unlawful pretty much everywhere, and harmful and abusive in no short capacity.
You're certainly free to say whatever you want, but if what you say breaks the rules, Riot is absolutely free to punish you as they see fit. Bear that in mind next time you try to bandy about freedom of speech.
and what they dont show is that the enemy draven was talking the same way towards me, as he was a friend of mine
Other people's misbehavior does not absolve you of your own, and it doesn't matter if they were a friend or not. You broke the rules, someone reported you, you got punished. Them's the 8r8ks.