First of all just giving a random account and says this is mine doesn't really work, because I can do the same thing. http://na.op.gg/summoner/userName=expectnoganks I promise this is mine see. Also that is the problem so many people have. I don't want to play against it so I will constantly ban it, but when I have to ban something else Yasuo is picked and it's hard to fight against him. But it's horrible to play with one. Secondly doesn't it just sound odd why someone is staying at G5? Maybe has to do I use this account to get to G5 and stay there? See the history G5 and then stays at 0 LP the entire time after.
Secondly Bronze and Silver players are a joke. Something is OP so it's impossible to play with against it. On my Bronze smurf I just had a Swain on my team bragging on how he climb out of Bronze 5 this is not a Minority in Bronze. It was just like Katarina she is too strong, yet a majority of Katarina's are so predictable its sad watching them get fed. Of course there will be smart ones that learn to not jump to the dagger the person is standing on to bait them.
Secondly unless I missed something All but the Q are skill shots, while her ult will only work if the person has already been hit People have to learn to dodge one day. So at most that ult will help, but will be easy as hell to bait others to their deaths. Also the short clip they show was more then likely letting her get fed to "Show Off" the new champion in a positive light. And since she isn't out on the PBE this is a Riot test game so of course they will show you the best of her. After all pretty sure we all remember Ivern's Release was garbage.
From the looks of her she has the same range as Draven/Vayne so any adc with range should be able to keep her at bay. Her damage all seems to be burst so janna/lulu should help with that or depending on what the Q actually is Shen's W could block a majority of the burst. Once she uses her E Leona could lock her down or Braum's E could block a majority of her burst. There are plenty of ways I can think of to stop her, but oh no she will be banned for 2+ weeks, because she LOOKS OP.