The champs you mentioned above are hardly impossible to kill.
Kayle is not a champion earlygame and honestly if she doesn't get punished for it whoever gets matched up againts her should uninstall, if the jungler fails to intercept the enemy jungler he should also uninstall.
Vayne is strong... if she gets ahead, on an even playground she's not that good againts lane bullies. Especialy the point and click ones. Champions such as Caitlyn, Sivir and Draven should be able to force her out of the game for the most part by smashing her in lane.
Kayn is not that strong... he does require time to get his form and before that he's actualy pretty weak, if the jungler abuses that Kayn can be put out of the game for a pretty long time. Gravious wound works pretty well vs red Kayn, any form of peel works pretty well vs both blue and red Kayn, just make sure your adc isn't too behind to kill him and you're all done.
But yeah one cannot controll his teammates so you first need to win the matchmaking coinflip which isn't even a coinflip cause you kinda flip a coin for everyone besides you so you get like 9 flips so the chances of winning the lottery are much lower.
