Hi boys, this is a very fast build but with wich I am having good success with. The name is SINKARTHUS because it comes from the merge between SINGED and KARTHUS. I am a hard nose singed fan and I decided to use his "gameplay" with karthus. This guide is different from the other TANK KARTHUS guides especially about the items.
So This build does A LOT of damage even if you just have 3 damage items (Archangel Staff, Rod of Ages and Liandry). In addition to these three items you can count on the "masteries damage" that are quite good as well.
In addition to the damage, you are able, with karthus, to build straight to 6 items, WITHOUT BUYING BOOTS. When you have your core items, you basically sell boots and get DEAD MAN'S PLATE. Like on Siged its passive is not going to end because your Q and your E basically don't affect it.
In late game you can sell the sunfire cape and get a Thornmail or a Magic Resist item depending on the situation.
So with this build you have:

- 250 - 350 armor
- Insane damage over time with you E active, Deathfire touch, sunfire cape, Liandry passive (forzen heart procs liandry), and Q if you are good at getting it
- High base damage, without yellow scaling health you can get to 3500 HP
- you can geto to 407 Movement SPEED without boots thanks to unlimited deadman's plate passive (don't autoattack, just SPAM Q and E always ON)
- insame amount of mana (archangel, frozen heart and Rod of Ages (plus the mastery mana regen mastery and E passive.
- Decent sustain with Catalyst passive
- Amazing wave clear