@sgt_ham: That isn't true, all of their attacks can be avoided. It requires some fancy footwork on your part, but it can be done.
4K is basically a pure DPS race at it's core. In a regular new game they aren't too bad because they have small health pools. However, NG+ gives each of them a very healthy bump up in life and greatly increases they odds of multiple kings being alive at once. You have to avoid this. I suggest taking on a offensive defense. Roll into their attacks and then strike while they are open. If done correctly the animation will protect you from the damage. Don't try to stand around and tank them. You will waste too much time blocking and could end up fighting more than 4 kings.
A guy comes on here and shares his first experience with a game and you all immediately start pointing out all the flaws you found with the game and saying what other games you think are better. I could have sworn for a minute that I was on /v/ and not Giant Bomb.
Anyway, I'm going to share something that is always useful to new players and can help clear up some of the more confusing aspects of the game.
Farm rats under the bridge for humanity. Or if you already have the key to the lower city you can try your luck against Capra demon and try to get to the sewer to farm the rats there. Next, make sure you have saved Lautrec from the chapel prison cell (he is on the upper floor in a little area that is slightly before the steps leading up to the Gargoyles) and have then talked to him again at Firelink Shrine. While at Firelink you should revive to human. Also make sure you have upgraded your flasks via the fire keeper if you haven't already. Then hop on the lift, take care of the few baddies on the way back up, and summon both Lautrec and Solaire. Only way you can lose now is to go full retard.
But that is just if you are frustrated and want to do it the cheap way.