for this build, you need to make your way to the cathedral of the deep and be invaded by long finger (the guy in spiky armor) slay him and then either go through the area and defeat the boss or homeward bone back to the cleansing chapel. Take the shortcut up to the roof of the cathedral (f you don't know how I will post a video in the comments) either run past or kill the 2 knights up there. drop down into the balcony type thing to the right, run towards the man grubs, slay them. and you will have to hit a fake wall. This also unlocks a faction, Once you hit the wall and run in you should see a shiny, simply pick that up and you have the sword needed to do this build.
Make sure you get this Barbed Straight Sword up to +10 and (trust me on this one) infuse it with a hollow gem. And reinforce to at least +9
This sword is already a pretty good straight sword and can be buffed and infused. With a +10 and hollow infuse with less than 20 luck I hit for 423-425, at NG+3 this is a decent amount for how fast this sword swings, Putting it into perspective without the bleed effect I can do 1300+ damage in half my stamina at the values listed above. ( if you do the math you get roughly 834 DPS )
With bleed, this jumps up significantly!
But onto how you use this. I ran the spike armor complete set with this. Shield and all, Once you have your stats at the minimum you can go ahead and buy either a carthus rouge resin (to enhance bleed) or you can buy the toxic resins ( Cannot remember the name ). With all of this mentioned above, you should be able to apply both bleed and toxic onto your enemy of choice. I personally love running this in bosses because it melts them. I used this build on the final boss last night and melted him in about 5 minutes.
Rings you want to run vary, Try using the hunter's ring and if you plan to buff using spells Lingering dragon crest ring. Others are up to you but those seem to really tie it together. Again I will post a link to a video showing you how to get to the faction where you find the armor and weapons necessary for this build.