Hello guys this guide is going to help you rule mid lane, and the rest of the field with karthus. Of course you don't have to follow this build 100 percent but this is a nice start to any karthus build, and my personal preference when playing him. Hope you all enjoy :)

Pros!
1. great farming due to defile and lay waste.
2. great harass due to lay waste
3. ult is global ( hits every damn champ )
4. he will kill you from base :3

Cons! O:
1. kind of squishy (ok really squishy but he is kind of meant to be.)
2. his ult can be stopped by good CC ( not that you'd want to cast it near an enemy )
3. well nothing else honestly. :3

So here is the lowdown on the items. With this setup you get a whopping 1000 AP yeah thats right 1000 AP! coupled with your ult that is some serious damage if timed right. gives you some health not that you really need it and some armor. I'm not going to really go into detail about what each item does and why you should buy it because it's all really self explanatory in the item description. Void staff for that magic pen, hourglass for AP and to hop into team fights and activate its ability so they surround you (if they are not thinking right anyways ;) and the rest for mass AP gain. during the beginning laneing phase harass as much as possible with lay waste. once you get the timing for it down its pretty lethal early on. Don't be afraid to recall when low on health because you have teleport. Most mid lane champs you'll fight against wont pose much of a problem at all which is a plus ^_^ my favorite thing about karthus is being able to die, get some kills, ult, hopefully get more kills then just revive and teleport back to where **** went down. once you get into mid game you should have deathcap and rod of ages if you're doing a great job and have a few kills on your hands. don't be afraid to ask your teammates on helping you with when you should throw you're ult up. just be warned some people like to get pissed at karthus because he is the KS MASTER. late game is where the fun starts. with your build nearly complete you'll have roughly 700/800 ap and defile and lay waste in their own will be killing and making the other team run away from you, let alone your ult dishing out massive damage to those foolish enough to think they can get away. This is my first guide and i'm not done with it yet, i jsut put this up as a start of things. I will be adding within the next few days and making it all pretty for all you people instead of just one chapter all mushed together. so please bare with me on this :3