That build would suck major bollocks.

Lets say you got 4500 hp, hurray. You've spent 9600 gold on 3 warmogs + 1850gold on atmas + 1000gold for boots. That's 12450 gold....

And what PD do you end up with? 0,02 * 4500 = 90 + 84 (which is her base dmg at level 18) = 174

Her ult will do 203,1 damage on each hit... (which is very little compared to other builds, and it doesn't even slow)
Shunpo will do 210 damage (lol...)
Bouncing blade will do 250 damage... (Hardly a threat)

And you got sucky attackspeed. I'd say you could just ignore a katarina built this way completely and kill her teammates. Worst tank ever, no stuns, slows, no damage, can't slow people either..

Stop this extreme Q_Q and read my guide to Katarina here.