I started playing Talon on my smurf acc and was able to climb 2 divisions in one day after I get my initial rank already.
AD Assassins are currently the strongest champions on field as they can oneshot squishy in less than half a second. However there are certain conditions you need to achieve that. If you lose lane or be even in lane where enemy adc gets fed you might not be able to oneshot him.
And because Riot balance team was so smart and gave us
, you must oneshot them because if you won't you get two-shotted in return, three-shotted if you are lucky. Or you need to use your kit in a way to not allow them attack you or just run.
Still until very late, when they get so huge lifesteal it is actually not so needed to kill them. Just dishing a lot of damage to 2-3 ppls, burning their summoners and then escaping without dying is still worth. If you weren't doing exactly great in lane and enemy botlane got fed then you shouldn't aim for the kill but for damage/summoners instead and abuse that in next fight.