Hello people and welcome to my personal build for the ideal Karthus.

Here I will describe my build for karthus,which I did after lot of thinking,playing lots and lots of games and trying all the kind of things to make him able to survive teamfights and do damage too.

If you read this guide I guarantee that 95% of the people will be better players after this.
I will update with more and more chapters every time I feel like want to share an experience

!!!!!!!!!!!!!!!!!!!!!!!!!!!!CAUTION!!!!!!!!!!!!!!!!!!!!!!!!!!!!
FEEL FREE TO ASK QUESTIONS,I AM HERE FOR YOU EVERY DAY!!!!!!

Pros:

Amazing CC after rylai's. (dude your defile will slow every single think on his way)
Can do an amazing amount of damage in short periods of time--->WITHOUT MANA ISSUES(at least not in mid & late game,i don't have issues in early game either,but some have.)
One of the best ultimates in game,chars who try to get away..not when karthus is here. :D
No issues for every team to have him,I mean he suits everywhere,of course we need a tank. ^^
He is scary.
Crazy passive,if you die you will still be able to do a bit more damage,or big,depends on how smart the enemy team is.


Cons:

Squishy
Costy itemisation(shouldn't be a problem if you farm properly though)
Focused first in teamfights,with no team coordination:die first too.
Some chars can own your *** easily(see tough situations chapter)
Ultimate won't kill the remainings every time...some chars & items have ways of defending themselves
Smart players get away from your passive immediately

OKEY guys let's be honest.

KARTHUS is an amazing champion that can kill almost every champion in about 3-5 seconds if build correctly but HE CANNOT CARRY GAMES ON HIS OWN AND HE WILL NEVER BE ABLE TO DO SO.

<<you are a noob,if you can't handle karthus you can't say that nobody else can>>
Go ahead say that,and let me answer with a video from a Professional player in the winner team of season 1 dreamhack tournament. Play Video go to 26:00 and watch karthus,did you notice him do any damage?
now go to 36:35 he dives in,and no matter how hard he tried to do some damage he died with almost nothing...killed?0.5 champions.

I think the way he engange was more of a nuke build..while he had a normal build according to his items...I don't say he is a noob or something like that,I think the main reason for picking karthus in the last final is to let him dive in first to do as much AoE damage with defile and some with lay waste and then the rest of the team with the support of his ultimate,to engage doing the damage left,but he wasn't able to deal any serious damage,so the plan didn't work,and they failed when they engaged.

He is Peke from fnatic...a world class player.If you think that you can do better than him...then you don't need that guide go play pro doing pentas :)

I can show you a lot thinks that prove my opinion but I think this is just enough,furthermore,we are not here to tell you what you can't do,we are here to tell you what you CAN do.

Because he is one of the few champions with good damage in every single spell he has,and an amazing wall which reduces not only movement speed but MR too!

I mean COME ON!,I don't want to waste such a good champion for some insecurities people have about his survivability

I believe that this build is good enough to compete,survive and do damage at all.

Here are the items and why I pick those.

Doran's Ring : well here is the thing,people don't like this item because is just a start item that you will sell as long as you will finish your last items,it's okey if you want to replace it,but you will have to be a bit more defensive because you know...without anything at start you will die way too fast...trust me i remember getting ganked flashing and then watching Hungering Strike plus a Transfusionand Sanguine Pool to get me at 50-100 hp,thank god that vladimir didn't have an ignite...that's right people,I used to start with Amplifying Tome and a Health Potion but no, better have 5 less ap, and have 100 health + mana regenaration instead at start.



Sorcerer's Shoes : Clearly ap boots,be sure to get that before Tear of the Goddess because MrP believe it or not some times can help you do some more damage,and because you are an easy-and-lot's-of-junglers-first-target,you need to avoid ganks.

Tear of the Goddess : some people don't like it and I don't really now why...it's an item that provides bonus mana,mana regen,and you will have your mana grow throughout the game so your issues will be gone + that you can build archangel staff afterwards which boosts your AP a bit more.Still some people say <<I am karthus I will obviously own the golem buff>> well if you think so don't build that item and go for something else for survivability like Zhonya's Hourglass or an early Banshee's Veil your call.

Rylai's Crystal Scepter : Now that item is amazing it gives a fair amount of ap and 500 hp plus a GREAT CC PASSIVE!!! you have slow in every ****ing spell..tip : if an enemy is about to escape a gank but your ultimate won't kill him,do it anyway to get the slow going,if you communicate through skype or teamspeak and tell your team not to stop hunting and hit that..you might be able to save the kill for them... slow from everywhere..now that's magic isn't it =)?

Rabadon's Deathcap : even with the 15 ap nerf this item is a mage choice and I tell you that:if your game is going great you can build it before Rylai's Crystal Scepter it will help more if you dominate a game,if you don't prefer the normal build.

Rod of Ages : classic mana-health-ap option will help you survive a bit more in teamfights..at least works for me :D

Void Staff : if any AP char doesn't have this item late game,then he is not a mage.

Maybe:

Mejai's Soulstealer : if you are against feeders,then build and gogo penta :D

Zhonya's Hourglass : there are fans of this item because it has a grounbreaking active plus a decent amount of armor and AP,but I don't really like it to be in my main items tree...your call if you like it..
But with the 300 gold reduction it seems a more viable item.

Banshee's Veil : I sometimes sell tear of the godess if I feel like dieing too much or I get focused all the time..will help a lot...especially against stuns or engange spells like Curse of the Sad Mummy, Absolute Zero, Unstoppable Force etc.
Actually,lately I start to prefer it way too much instead of archangel staff for late game.

Will of the Ancients: really nice item ... well I actually prefer somebody else in the team to have it..but if no...no big deal my opinion for both spell vamp and lifesteal is that in teamfights won't help,I mean come on it's live or die...if you get in and you are focused not even 100% spell vamp will help you...but it won't hurt you if a support or an other AP carry gets it,it helps you and it's funny to use your ultimate to heal yourself :p

Quicksilver Sash: This helps very much it's an amazing item for suppresions,works great against Warwick and Malzahar ultis.

Abyssal Mask: if you are a more survivability player go ahead it has a nice passive too,but I don't like it for one reason and I don't know if I seem stupid:in pre-teamfights situations when teams try the better way to engage to succeed this thing shows where you are...like Fiddlesticks A Harmless Scarecrow,and apart from that,replace an item of high AP for a 70 AP and 57 MR will start making you an offtank...but it's a nice item...your call

NOT POSSIBLE OPTIONS:

Guardian Angel:Dude if you lose a teamfight that item won't help you get it back they ll just wait for you to come up again and kill you twice,you are not a tank you will die so easily that this item is just the cheap replacement of Zhonya's Hourglass if you are focused too match guardian won't help as much as zhonya's just tap it when you are focused and 'll see the difference.

Thornmail:I consider every player which is not an offtank-tank OR MAYBE(I even doubt about supports)supports,taking a thornmail,a weak unskilled player,well if a Tryndamere is fed you can buy a zhonyas,but a thornmail has gone too far,I believe that thornmail is for big hp chars because if you are focused by a fed AD carry then your tank isn't that good to stop him,or you are not good enough to kill him first,or someone fed him,in all 3 situations,thornmail is just not an option,just weak's player option.

In this chapter I will explain what to do if you face tough situations with champions that play offensively:

Against anybody:Think of any char who plays offensive,if it's not one of the listed below then he is either scared of you or has too much self confidence in both situations you should play smart,be cautious,do your farming and for god sake,do not show that you are scared! IF YOU SHOW THEM FEAR THEY WILL DRINK YOUR BLOOD AND **** YOUR ***,harass,show them who is the boss here don't make them feel overpowered...

Kassadin:pain in the ***,if he attacks you MOST of the times he is scared to let you farm, but think one thing against him,at first levels he has only one ranged attack,...he will attack and you will probably see the damage and back off..but what I do? i wait for the silence to stop and I Lay Waste the hell out of him...if you are lucky enough to land 2-3 mines...see if he will come again..., Wall of Pain and start Lay Waste again ,he will probably around 1/3 of his health if you do all the steps correctly...now you have 2 choises play defensive doing your farming,or play offensive trying to flash close him and kill him...if he plays defensive then he is scared,last hit when needed and every other second throw mines at his ***,remember laning phase that has no kills has only one winner,the guy with the most minions...so think if someone harasses you and don't last hit,if you are good enought to avoid him,then you will be the winner no matter how many times he was so close to kill you,he didn't so...0-0-->Extra time-->Minions killed
Tip : if you are low and a teammate asks for Requiem don't forget that kassadin's ultimate combined with a flash can get him from center of mid to your turret immediately and kill you,so prefer to go to the next turret,better have 100% survive chance and 50% to kill him instead of 30% to survive...and if you do survive have a 80% chance to kill the enemy...
Vladimir:Damn that's what I call anti-karthus char,you Lay Waste he Transfusion you use Wall of Pain he uses Sanguine Pool,don't show that you are afraid but don't be offensive just ask for ganks,and try to farm,if he doesn't kill you then good job,if you kill him...man to kill vladimir you need to be super lucky...not only he has a spell that takes health back for him,BUT you can't hit him with Requiem for two main reason,if he escapes with a small amount of hp and you use it he will come back killing you because this will be the only solution for him and he will suceed 80% of the sitautions...well if you go back to your turret then probably Sanguine Pool will be refreshed or he will Transfusion,well sometimes if you do this fast enough maybe Sanguine Pool won't refresh and if Transfusion won't heal him more than 230-250(that's your ultimate damage at the first levels)then you will get the kill but you need luck-speed-skill to achieve such thing.
Tip:same with kassadin but this time with Sanguine Pool,don't risk yourself for a possible kill.
Annie:stay in range and last hit,if he comes for you back off,then if he follows for long just ---> Wall of Pain(before he stuns you otherwise 90% is too late to do it after the stun ---> Lay Waste if you are good in landing that mines then you probably made him think twice the next time he will engage,but DON'T FORGET LAST HIT,some people are afraid and they don't last hit they just stay there,well dude if you don't last hit then you are losing the game anyway,if you are not able to farm against the guy you face,then ask for a change,or change tactic,you can't just sit there,a guy who goes mid or top and doesn't farm,he **** the whole team...
Malzahar : not a lot you can do,just farm and ask for ganks,if you are below half health and he hits level 6,well either you go back or Nether Grasp plus a skill combo --> game over,so try not to take too much damage from him,remember that he has skill shots,try to avoid,plus avoid standing near minions infected by Malefic Visions because they might randomly stick it to you and you don't want that right?
tip: malzahar has 2 skills which can stop your ultimate so like always...back off
Nidalee: If you have problems with nidalee then you must be like rambo or you are just afraid there is really no reason to be afraid of her,he just has one skill Javelin Toss,stay behind the minions and even if the minions are not there,you can avoid it,it doesn't have enough speed to make you unable to react,it's actually really slow so after he throws the spear ? nothing that deals serious damage...right?,now about the cat,now to avoid this you need range,if you see her going close to minions just to farm with cat form,then you should harass his *** off,you are range and the only way to get to you is with a 1 meter jump,which don't actually helps the situation,if he engages you with cat form then back off and start harassing,if he is getting low attack but if he has for example 150-200 health no need to waste your ultimate,he will heal himself immediately,so waste of time,it happened to me twice yesterday and I gotta admit I was pissed off,
TIP!: IF YOU DO YOUR ULTIMATE IN THE FRONT TURRET THEN YOU ARE 99% DEAD, Javelin Toss DANGER!!!
Anivia: avoid Flash Frost it's super easy if you keep range just stay out of the way and if he tries to Frostbite then take the damage because his skills are in cd and use that time to Lay Waste his *** off if you have enough mana then Wall of Pain too,and see that overestimated char to Crystallize to save his ***,if he does well you continue harass you are karthus your mines have crazy range,and by the time the wall gets you out of range it should melt because it's only for a bit,anivia players level Crystallize once and keep it there till everything else is maxed out.
Kennen: avoid him if he tries to do the think-fast-skill Lighting Rush wall of pain and mines,and like always you can avoid his skill shot,your skills determine the game. :)
Veigar:that tiny little thing is the most powerfull char against AP chars, if he hits level 6 just know that you die if he has enough mana to do the combo Event Horizon --> Dark Matter ---> Primordial Burst ---> Baleful Strike so care and ask for ganks he is super squishy and you can kill him,at lane phase try to avoid the stun if you let him get you twice then you are in danger zone(if you ain't dead already)so if you see him getting in range but not using any skill,he probably tries the E-W-Q combo,move randomly to confuse and try to harass him so he feels you too.
LeBlanc: exactly like annie,back off then wall,if he uses W to go b then he is wasting mana,but your harass skill depends a low amount of mana remember? so no worries,if he runs out of mana show her who is the boss and farm like king while trying to ruin her farming.
Cho'Gath: avoid his Q and you are just fine,if you avoid W too then you can harass him with 2-3 mines,and remember that Q-W-R is a deadly combination,so don't let him get too close,even if you are full...

That's all folks,all the other champions are extremely easy to mention them remember,almost EVERYBODY has cd on his harass skill while karthus don't,so use this,make them thing(I CAN'T STAND NOWHERE WITHOUT THIS MINES UNDER MY ***)

Note: If you have a problem facing any champion just tell me in the comments section,I would be grateful if I could help you

Karthus is karthus and he needs mobility. He is a super squishy and almost every time first target in teamfights,so I get Flash because it's an amazing spell to get you out of teamfights so you can re-engage while someone else is focused,and I use Ghost because not only it helps you avoid early ganks,but because it's a run-chase spell,and helps same way with flash in teamfights.

Other possible spells :

Cleanse: I don't like it but if you do take it but please let me explain why,if they gank you will cleanse help? well maybe,but late game you will lack of a good spell cause you have cleanse,in teamfights no matter if you clear all the CC by the time you will try to do anything you will be down.

Exhaust: Can turn the table and has no limited use,I was using it lately but I decided that better let it for the ad carries,after all,ghost can help you chase and run,exhaust can help you run against one target,against 2 or many?

Ignite:I might use it if I see a fiddlesticks,mundo in a ranked,because fiddlesticks hates ignite,it can help in early game to let you get that FB but then it becomes useless...

Teleport: karthus players like this spell because they can a save a turret and farm minion waves more effectively,I just like to walk my way there because I find teleport pointless. :)

Non-possible spells

Heal: you die so fast that you won't even notice it,

Rally:This thing needs to get out,nobody uses it...

Fortify: I love that spell but I don't think anybody should use it anymore,instead of fortify to save a turret,go farm the minions,if the minions take down the turret then is your fault,you shouldn't let that lane so unprotected.

Thanks to complexicate and Searz we now know which runes work for what https://spreadsheets0.google.com/spreadsheet/ccc?key=t_xRULj-sC-SoHKcQGxNUgQ#gid=0

http://www.mobafire.com/league-of-legends/build/rune-tips-what-secondary-and-primary-means-and-more-24255

So there are runes that are better at marks and some other are better for glyphs etc.If you are not convinced

For Marks,the better choice is to get magic penetration.Anything else is pointless,so Greater Mark of Magic Penetration

For glyphs, normal CDR seems to be better,but I choose CDR per level to get -3% more at 18 lvl,don't worry for the weak start you won't need your ultimate because it only deals 250 damage.. that much till 11 level,at 13 level you go to 0.65 and you tie the other runes so when they are actually getting useful,then they start to be better from normal runes,but still,your call,so for me it's Greater Glyph of Scaling Cooldown Reduction

For seals,I choose HP per level but MR5,MR5/lvl,Armor are viable and all work for karthus their own away.but they give 19.54*9 = 175 health,that seems perfect for me,but if you want something else from the abone np,but I don't consider mana regeneration to be a problem and armor doesn't seem to do anything if you put some armor,after all if you block some damage,it won't be a groundbreaking amount nor AD carries will feel like you have armor,I say they won't even notice it,so seals for me are Greater seal of vitality

Quintessences = here some prefer AP per level,I consider AP per level amount isn't that big deal...I mean you can have 15 Ap from the start,but will you choose 21-22 ap it's a 6-7 ap differense and you get it at 18 lvl...worth it? I don't think so,and that's how I end up with Greater Quintessence of Ability Power

Death Defied: when you die,throw a mine,do ultimate and then if there are still people try to do as much damage as possible
Lay Waste: this is your main harassing tool,and a really cool farming skill if used properly,care not to overextend for harassing or miss creeps just to harass,but nobody mind if you harass them a bit too much,after all,it has no cd :D.
Wall of Pain: this is the perfect combination with Lay Waste the enemy goes so slow,even if he tries to avoid the mines he won't be able to do so,if you have mana for Defile good,go with both and watch them die slowly slowly...
Defile:If you stay alive enough to do damage with this then great,teamfight is won,but most people won't let you,it takes both skill and speed to be able to do a decent amount of damage with this.
Requiem:this is karthus SIGN, every single guy pronounces karthus says<<the freak with the pathetic ultimate>> use it as often as possible,don't just have it for rare situations,better use it 5 times instead of 2,what if you won't get the kills you will still help your team.

If people rage about your ultimate and generally hating karthus remember one thing,<<hating is the gun of weak and jealous people>> whatever you hear whatever they say,treat them like they don't exist..what I do? every time I get a kill and they rage at me I throw a (<3) and I yell to my partners on skype NOT TO TYPE ANYTHING!,why I say that?I am not a psychologist but I can understand that if you type them,you feed them with attention,they need attention,if you treat them like ****,they will get angrier and angrier,rage=mistakes=opposite team wins :D
It's always better not to type anything,personally I just can't resist xD!

Be sure to take the magic penetration from offense and then maximize utility making also sure to take ghost and flash upgrades,other are your choice,I consider movement speed to be a must,that's all,classic mage 9/0/21. necessarily

Early game your team invests on you and you have to be able to do the damage late game so...
FARM!!!!!!!!!!! what if you can't get to kill him,15 creeps are like a kill,so don't overestimate the power of killing someone,sure he will lose some creeps too but don't give so big deal to it early game,sure if you can go for it,but not necessarily.


CAUTION! if you notice what was happening in dreamhack,now teams don't have a time for gank,they might try to do it in 1 lvl,maybe in 2-3,anyway, always care.

Tip: this is easy and all the world class teams are doing it,smart players don't hit the minions all the time,they just last hit,why that happens?well if you hit more then you will push the lane,and you will be more vulnerable for ganks,plus the enemy will be safer,if they push you,your jungler will find it easy to gank,let's say a WW turns 6 lvl,you are at your turret last hitting like always,the enemy pushes you and he feels control,now warwick comes and the enemy flashes immediately,warwick comes from the middle so the flash won't work against WW ultimate,so you engage with a flash if needed put a wall and start Lay Wastewhat will he do?most of the situations he is dead because he is far away from the turret.

(CAUTION!!: IF YOU SEE SOMEBODY COMING FOR GANKING THE ENEMY NEVER GO HIS WAY,NEVER!THEY UNDERSTAND HE IS HERE IF YOU ARE ACTING WEIRD LIKE GOING NEAR THE BUSH!!sometime even if you click once towards the bush and then again randomly somewhere else they will back off,so you know,act like you were acting the whole time)

Tip:wards win games,having a ward in bushes will save your ***.If he comes from the sides next to your turret,your reflexes need to be fast enough because if he is warwick,he will flash-ulti,and this is the worst situation can happen to you,all other chars from jungle can shout demacia,can throw gunshots from the sky they can do lot's of things but you can avoid them.

Farm but you can try a gank, most times I gank when I recall to town for the first items,if they are warded in both sides and your team knows it rush with ghost so they won't be able to react,or try to go from another root,use your imagination with flash and you might achieve a gank,remember you are able to know the range of your flash spells by scrolling your mouse over it,so why not?

Note your team to ward dragon,if they enemy go for him and you can stop them this will be great,don't underestimate dragon,it gives 1050 gold to the team,gives a 1k gold advantage,that's huge isn't it?

If you can ward baron too,some teams have strategies to get him early,but I believe no team should be able to take him down while he is warded(they might be able too,if they win a teamfight),low lvls:more time for your team to react,so you can run towards them and force a teamfight with them having baron aggro,even if they are not,they will still be low enough for you to have the advantage,don't let them get baron that early,will be devastating for your team.

As karthus now you care,ganks are really hard to avoid as turret dives start,furthermore,have map awareness,if a teamfight is about to begin,be there,remember you are the gun,the tank holds the guns and you need to shoot them before you go down!

Here is when it gets tricky,NEVER FORGET,NO MATTER how advanced your strategy is,the main goal for both teams is to get down the enemy nexus,every single thing we do is to get us closer to it,so here teams will try to:take baron,take dragon,push if you did a mistake and you let a lane to overextend and the main goal,win a teamfight,the win of your teamfight will be measured by one thing,what you did in early and mid game with the turrets if you took 2 turrets from a lane this might end even to a game win,if you took out 1 then you might be able to go for the inhibitor,if you didn't get any then you just get 2 turrets from a lane maybe 3,depends in how fast is your team,and if you have a warwick, Hunters Call is really helpful in taking down turrets.

Karthus from all these should focus in 1,win the teamfights,this is the time to prove your team that the invest was successful,so try to carry out as much damage as you can to get them down.

Some people complain about mana issues throughout the game and I don't really know why,for that you can either build tear of the godess instead of Banshee's Veil or demand the golem buff,but if you get into a teamfight with the amount of mana that Rod of Ages gives,plus your normal mana and the mana of the two items I mentioned before,well only if the teamfight take about 2 mins to finish then you should have issues,but still,this is almost impossible,don't forget Defile on while is useless,it's a huge amount of mana wasted and we don't want that.!

Remember you are your team invest so farm farm farm
Don't stop your farming in useless harassing but if you can go for the kill go,remember last hitting creeps is important too!

You need to stay alive in teamfights as much as you can so try leaving and re-engaging so the enemy team focuses someone else,if you did everything you could and the enemy team got the teamfight,then you didn't try enough or your team has feeders. :p

Gankink with karthus is viable but you won't success always,try it out.

Everything needs practice,map awareness,reflexes,judging what you will do next so your team will benefit the most from it,so you won't become the ideal karthus from the first game,but if you try time will make you a great player,personally when I face karthus,I own him 95 % of the times,but I type down(don't worry karthus is hard give it some time) and they are like(lol man you play exactly the way you must against me),I feel bad I really do,but I try to encourage them,because most of the time they end up in their turret while I farm like king,this happens because they come to the lane with a Sapphire Crystal dude you have low hp pool,you can't survive by spamming spells.

That's all.

In this 16 chapters I tried to improve your gameplay as much as I can and make you all better players,but you won't be able if you don't practice! Karthus is a player that everybody can play,a smaller number can try to learn him,BUT,ONLY a few can master him,the patient,if you master his combos,then he is a great AP char for every situation,he can turn the tables by pressing just one button,he is a game changer so...if you want to be better you want to learn that guy,because people fear the unknown,if you know someone and what his moves are you can face him,because a good karthus in a lane is a pain in the ***,his Q never is on cd.

Finishing,I would like to say a few things about the raiting,I don't care if you upvote if you downvote,as long as you tell me why giving reasonable facts.

Thank you for reading my guide I will say it once again,feel free to ask questions I will be online most of the time.

Have a nice day :)

So,finishing the build you can do it by 2 ways,the way you judge will determine your gameplay

1.Finish the archangel staff and carry out 750 AP,3.2k health and almost unlimited man,with baron and a golem buff you are like a god in there,sick isn't it?

2.Go for banshees and finish with up to 3.5k hp,decent magic resist and a magic shield that will stop single CRAZY damage spells like Summon: Tibbers, Mimic or Sigil of silence, Requiem(you might not be the only karthus :x)etc.

My personal opinion is:You own the game?go 1,wanna play serious go 2,most of the times you should go 2,but if the game will go better if they are squishies while you have 750 ap can lead you to a --> Flash--> Defile--> Wall of Pain--> Lay Waste--> Requiem,dude if you are able to get 5-6 mines and the defile on em within 10 secs and requiem,well with 750 only guys who stack MR hard can survive,and that is your main goal,with a tank CCing them you will achieve what you want.

Changes

1.000 Created the build
1.001-->25/7/11-->Added chapter Final Stats