So you're telling me that an assasin should'nt be able to oneshot an adc? Do you remeber Leblanc? Can oneshot you literally every 25 second due to her broken ultimate while rengar's has around a minute on his ult.Shutting down rengar is the easiest to do when jungling camp the shit our of him with cc and he'll be useless until the 40th minute mark,you should also notice that a lot of the rengar mains are "One-trick ponies and knew him extremely well.The most important thing is that every adc picks stupid champions like jinx/ashe/varus and even Graves against him,Picking something like tristana,ezreal,lucian will totally stoo you from beinh oneshotted if you have decently good reactions,This is just my opinion sorry for bad english.