You mean, why Kat isn't even that viable anymore?
Learn to use Zhonyas. gg wp you win.
But, last I played Kat, I can see why you think she's a god.
Q allows for poke and the tag along with W allows for some early game kills and nasty late game damage. I've taken down Squishys at full build with just q and w alone. Her E allows a hasty escape and go to chase, as it also targets minions and towers iirc.
Then her ult. That AOE doe; If it still scales how it used to, Double her current AP, and when it's up anything without a bit of Magic Resist is gone. Health bars be getting chopped. Her passive, which cuts time off abilities per kills, allows for swift q and w combos and after a triple or more your ult is basically refreshed. Spell Vamp can also work on her to allow for safe sustain and Katarina to basically never die. Not to mention she has no Mana or energy system. Goddamn.
Too bad her Ult is easily interrupted by a snare, knock up, or made irrelevant by Zhonyas. So bait her ult and you basically win the battle against her in most cases.
Am I the only one who stomps Katarinas as AD champs and AP carrys, but also Stomps when I play Kat? (Considering I main her)
Don't forget the elo factor
Most people that elo don't even know what karthus does.
Safest Fatman