good build, but I have a question: why so many archangel staffs: they have a unique passive that does not add to the mana, and with out really high mana 3% does not change the AD that much over another item that gives you other benefits.

I see other people going into other builds, but, this build literally works for 99% of situations, I've now tried the other builds and don't find them nearly as good as 1024AP defile team fights... Pentakill's FTW

Amazing build, Karthus has now become my main :P
Thanks

Why do people vote down without telling what they dont like?

First good Karthus build I've seen in a while.