Noh, i wouldnt buy Mercury's Treads.And also, not Zhonya's Hourglass that early.

Thats why I have the spellvamp item in my build, to get you the much needed HP... Having HP items won't get you back up if you get poked hard, spellvamp items do however. And if you manage to survive with little HP left you can hope to get some good hits on something to build your HP back up again. OF course it won't save you if they have a hard nuker but besides those I already mentioned the only one capable of doing this is Annie. -- anyone would go down even with rod of ages if the whole team focused you.

Flash, exhaust, spellvamp, wal of pain, merc boots and zhonya's ring are more than enough survivability you will need in most cases (exceptions explained above) -- besides it is kind of your job to die in teamfights, or are you saying good karthuses have no passive?

Note: will of ancients will help your team ALOT, not just you.

Besides in the campionship games I didn't see one good Karthus (I didn't watch them all but at least 3 of them had Karthus in them) They didn't do very well with their basic Annie builds.

Well anyway, I've done just fine without any hp items so far. My win/loss ratios are quite high on wins.

you always need to build hp. wall of pain wont save you from the whole enemy team when the focus you down right away. the most advanced players in this game will usually have 1 hp item in their build...

You wont be needing the HP if you just master the Wall of pain usage --- which makes this guide aimed for a bit advanced players.

I would suggest something HP oriented. Rod of Ages works wonders, because it gives you everything you need. Just the armor from Zhonya's isn't going to make you tanky without some HP backing it, plus you're still able to be nuked down. I'd push the Will of the Anicents back and put a Rod of Ages in before it.

Besides that, not a bad guide. :)
Check out my Jarvan guide in return?

Nice guide! thanks