Let’s play a game.
I name a hero and say, which hero he counters.
And then you say which hero is countered by previous countered hero.
I start:
Medivh counters Garosh, because no matter, how hard Garosh tries to catch someone, Medivh will save ally by portal and shield. + both his ults are helpful in this way.
Genji counters Kel’thuzad.
KTZ has a giant hurtbox which makes it incredibly easy to hit all 3 shurikens, it is especially deadly with the shingan talent.
If by some miracle genji gets chained, his reflect guarantees his safety.
Brightwing counters Genji: point and click silence with optional 25% armor reduction. Also Spell armor reduces chances for E to kill, whereas resets are harder to get.