If a counter relies on 1 ability...

It's not really counter.

for example, 1 of the oldest "hard counters " in League is to . That's not really a counter though.

The way it works, is that Yi is an AA champion, so counter-strike/blind will negate the damage. While Yi is blinded, Teemo does OP poison damage to him, to kill him because he needs his lifesteal to sustain. Same goes with Jax, makes Yi whiff his attacks, destroys him while he's stunned.

With good timing by Yi, he can Alpha Strike before the stun goes off and before the blind missile hits him, then he'll win that trade every time.

The reason inexperienced Master Yi players get destroyed by the likes of is because they engage with Alpha Strike (using it as a gap closer) instead of using it to dodge CC from certain champs.

Think of as 3 of the same. is 100% capable of engaging with trickster/playful, but then he's vulnerable. Good Fizz players know it's better to walk up. can gap close with rapel, but like Fizz, she'd be vulnerable afterwards.

^ Exact same concept with Master Yi. If you die because you used Alpha Strike as an engage tool, you deserve to die.

In the specific match I was playing, I was able to 1v1 Yi late game as . Against an experienced Yi, this is suicide every time. But since this Yi gap closed with his Q, I was free to land Q then melt him while he was stunned.

I'll admit, there are a lot of for sure hard counters, but when it comes to champions like , them being countered by certain champs is more of a mistake on the summoner's part and not the champion's kit.