I have to say it again! Your guide just rocks!I got a quadrakill and a triplekill in this round
and had 828 AP in the end.

PS: I hate RoA .. and it isn't in your guide which makes the guide even better ;-)

I thought the guide was both informative and well written. Also, I found it much more enjoyable to read than the current #1 rated guide which seems to be written in the most immature and annoying manner I have seen. Your explanations were to the point, and the layout was appealing. Thanks for the great guide.

That's why its stupid to turn on Defile at all early game. I said this in my guide. I hope you didn't downvote me just because you also have a Karthus guide. :(

Your early game won't have any extra mana, making Defile very costly. That means you'll have to back a LOT MORE, and your teammates will have you because they'll be like,"Dude, why did you go b? We could've killed them. ect".

I vote again. Karthus had become my main char and I still use this build.
If you really want to add a guide to play against specific champs in mid, maybe I can help you with it, if you want me to. Just write me.

anyway...
As I said I always use this build, but I do some variations on it sometimes which you might add to this guide.
- I always start with boots and 3 pots because of the mobility.
- If I face a veigar or some character with hard stun I use to buy a quicksilver-sash right after the tear.
- I use revive and Flash as summonerspell because after I die I can use the full 7 seconds to lay waste and spam spells.... revive and press R -... as your guide said ;-)
- I swapped the void staff (If I dont buy a quicksilver-sahs or a thorn mail) with zhonyas hourglas. Pressing E, flasshing in a group of enemies and then activate it is fun ;-) (okay, after the shield wears off I am dead instantly...but I can still participate in the team fight). It is a great opener for team battles.

(btw, english is not my native language.. sorry if I made some typos)

Good build! It really helped me get used to Kathus, because I believe Tear of the Goddess is crucial for Karthus! +1

Thanks for all the replies! I have a little bit more time this summer than I did during the school year, so I'll be updating this guide some more. I'm thinking about adding a section on going up against other mid champions. Let me know what you think. Cheers!

I've read a lot of guides and i've played a lot of ap mids. None of the other guides on karthus here on MOBAfire made any sense except yours. Its a really great guide, keep up the good work ;).

Great build

I personally think this is not as good as the other builds here, sorry.

void staff main? no updates? ....

This was great, and this build worked far better than that wack one that has the number one spot.