I use this build with Karthus and usualy go around 30/5 and u get about 1050 ap.

If you want other items I think Rod of Ages and Rylai's Crystal Scepter are great items for the HP.

So Clarity and Teleport are good for Karthus because you can always have mana in lanes and stay there for a long time.

These runes are great early game because you can deal a lot of damage early game.

I've never seen a Karthus jungle and I tried it and failed.

Usualy Karthus does great in Mid, but some characters are hard for him like Caitlyn with her range , Kassadin with his burst and the nukes like Vieger.

Farming isn't really needed because you will be getting a lot of kills but whenever there is a lot of minions you should go and kill them fast with Defile.

I think Karthus is a great champion and always tell your team to tell you when someone is low.Karthus can deal loads amount of damage with this full build . One time i killed tf with 2 of my lay waste. He is good early mid and late game. If you don't have a tank or your tank is really bad you can initiate and when you die you can pick up kills with your passive.

Thanks for taking the time to read this super duper long guide and I hope you enjoyed it :) smily face!!!Comment and I'll make more guides just say which champions you want me to build and I will make the most superest awesomest yummy and greatest build of all time. League of Legends name = I cont0lz I (the 0 is a zero in cont0ls)

There you go the best Karthus build ever tell your friends your mother your father your brother your sister your cousins even your pets can use this build and be successful!!! You will never want to be anyone else again!! Unless.... you are to great and get tired of owning people !!!!! Well good luck with this build and have loads of fun! ba bye!!!! Love you guys!!!