General toxicity is a climbing issue, especially during pre-season.
People seem to turn their brains off once pre-season starts, acting as if the game isn't even a competitive game any more. They aggressively talk trash, tilt after a single death, don't bother to do things such as ward or call MIAs from their lanes. They'll do their best to try and turn the enemy team to reporting you if you did so much as said 'Maybe it was a little bit your fault' by lying, saying you said stuff you didn't, and some of them go as far as to try and send the recipient of their toxicity a friend request or match invite to continue downtalking them if the person decides to be mature and leave the lobby rather than stay and argue. In ranked. This wouldn't be an issue in normals or whatnot, but ranked still sets your MMR for the next season even in the pre-season. Even if there's no rewards to be gotten any longer, you still shouldn't play ranked just to be a meta slave who screams at anyone who talks, even if it's polite or constructive. Take for instance; Mid lane misses an SS but your jungler catches them missing and calls it instead. Mid laner proceeds to berate the jungler, acting as if they had personally insulted them and their intelligence. (I dunno about you, everyone misses SS calls.)
Secondly, the way that Korea plays seems to have a mostly negative impact on the NA server, especially. There's a reason why silly builds work in Korea; they're really good at the game. If you are in NA Silver 4, you are NOT GOOD ENOUGH FOR A KOREAN BUILD. A side-effect of this... Koreaphilia, is the idea that if your bot lane loses first blood to the enemy bot lane, it's GG and you need to ff at 15. Your bot lane will either intentionally feed, become verbally toxic as if it's the jungler's fault somehow, sit in the base doing nothing but wasting cooldowns, or any combination of the three.
And as a last thought; With the recent change to runes, games are lasting longer than they did back at the beginning of the season, a ten minute lead does not guarantee a win/loss any more, and many people need to get themselves out of that mindset. Certain champions certainly do have an easier time winning than others, thanks to synergies with keystones or recent overtunings, but that doesn't mean that they're impossible to beat. It just means you need to play your teamfights well and throw enough stuff at them that it's impossible to dodge it all. Overpowered or not, abilities do have cooldowns. Unless you're Katarina. Ahem.
Lemmie know your thoughts on the state of the game, what champs you might think are overtuned, or even opinions on what could be done to make certain runes not pick-or-lose.