Their Pain is my Pleasure!
-Karthus

Hey guys! This will be my first ever guide in MobaFire and I would like to share to you the secret into dominating a game with Karthus, The Death Singer. I have played over 100 games with Karthus and I can tell you that I know this hero very well. He is one of the best AP carries in League of Legends and the hero that contributes very much in team fights. Karthus is a game turning hero; do great, and you can lift your whole team; do bad, and you'll be a walking free kill for every hero. He's also quite a mid-late gamer because it is with level that spells the boundary of kill or epic fail for this champion. So without further ado, welcome to the Karthus guide: Every Second Burns. This is a summarized guide because I don't think that a wordy guide means that it's a good guide. Read the whole guide, trust me, you won't regret doing so. (I've edited this guide since it's quite boring last time, i mean, sorry, it's my first time)

Pros of Karthus

1. Great laning ability.
2. Great damage output in team fights.
3. Can beat mostly anyone when they get on a 1v1 situation with him.
4. Global, massive damage ultimate.

Cons of Karthus

1. Really Squishy.
2. Vulnerable to CC's.
3. Has only one CC
4. Lay waste is hard to land when opponent is very mobile
*CC - Crowd Control

Exhaust

This summoner spell is great for catching up to opponents and because of Summoner's Wrath, this spell would also inflict -10 magic resist to your opponent. A nice choice to pick up a kill easily.

Flash

The most famous summoner spell of all. This is a great help for chasing opponents and to avoid being slain by the enemy.

Why not Ghost?

Ghost is also a good spell because it can be used offensively and defensively but if you will ask me, exhaust is a better choice because of its magic resist reduction to the opponent. Also, flash is a better spell because it allows you to pass through walls and avoid ganks much easily.

How about Clarity?

I might have said that Karthus is a mana hungry hero, but doesn't mean you need to pick up clarity. Besides, you already have the good passive of defile and with the items you'll be picking up, your mana will be able to sustain itself. (Don't forget you also alloted mastery points to Meditation)

Ignite?

The 70-410 true damage might be a good help in picking up a kill but if you will replace exhaust with ignite, it would mean that you could land less Q's and the damage of defile. Also, exhaust has less cooldown so you can use it more frequently than ignite.

Uhhm, Revive?

If you'll be picking up revive just to be able to use your ultimate, then NO! You'll just waste it. Exhaust and Flash would be more essential, also, you can still cast skills even if you're dead. Thanks to Death Defied

The Other Summoner Spells are too obvious to explain and are self-explanatory

Offense

As you can see, the mastery points I alloted in offense are all skill/AP-related. Due to the fact that Karthus is an AP carry.

Summoner's wrath:

The extra -10 magic resist will help alot in earning a kill

Sorcery:

Cooldown reduction to allow you to cast more spells in a shorter period of time

Blast:

For that extra 1 AP per level

Arcane Knowledge:

For some more magic penetration[/h4]

Havoc:

To inflict 3 percent more damage

Mental Force:

For that extra 6 AP

Spellsword:

To convert some of that AP into Attack Damage

Archmage:

To increase your AP some more

Executioner:

To inflict some more damage when the opponents have low life

Defense

I didn't alot a mastery point in defense since like I said, you're an AP carry, not a tank.

Utility

Improved recall:

Sometimes half a second can spell life or death for a champion

Meditation:

Since Karthus is a mana hungry hero, he will really need this mastery

Summoner's insight:

To be able to use that flash more frequently

Artificer:

Since 2 of the suggested items have long cd's, this mastery would help a lot

Marks:

Magic penetration. Do i need to say more? 7.83 percent of magic penetration is really not bad. Plus, it gives you an edge against all types of champions since this type of rune ignores the magic resistance of an opponent, not to forget that Wall of Pain also reduces the magic resist of an opponent.

Seals:

Why scaling health? As I mentioned earlier, Karthus is a very delicate hero. He is very vulnerable to both AD carries and AP carries so to increase survivability. And as we all know, higher survivability = more time to punish the opponents in a team fight. Why scaling? Why not just flat? The main reason for this choice is that opponents grow stronger as the game goes by. As they get stronger, there damage output increases meaning that you would need to have larger health to be able to accept all those damage. I chose scaling health over flat health seals since flat health only gives you an edge in early game and Karthus is not the type of hero who goes head to head in the early phase of the game.

Glyphs:

Scaling AP vs Flat AP. +9 ap is not too noticeable in early game since Karthus is a champion that doesn't fully consume his AP when having additional skill damage. You might be thinking, scaling ap will only give me +1 ap at level 1! That's true comrade. But at lvl 10, scaling AP beats flat AP already. To think that team fights mostly start when you're at lvl 10.

Quintessences:

What? Should I speak more? Go for flat ap! +15 ap is a big factor in you're gameplay (don't forget that masteries add another 6 ap for a total of 21 ap)

Why Max Lay wastefirst?

We max Q first mainly because you will need Q to have an easier time farming.

Why Not Defile?

In early game, you won't have that huge amount of AP so defile won't inflict that much damage compared to what Lay waste can. And if you don't have enough ap, you'll just deplete your mana quickly without even inflicting damage.

What not to forget

A clash suddenly occurs, what do you do?
First of all, don't forget yourNever forget it. And never ever ever use your in the middle of a clash or you'll just get it canceled. Either use it after dying or when the opponents are already fleeing.

Starting Items:

Why start with sapphire crystal and 2 health potions? The extra 200 mana gives you more spamming ability to land those Q's and grab some creeps or harass the opponent. You might be thinking, but Karthus already have defile. The passive of defile might be great but you need it to get to lvl 4 before the mana restore can exceed the mana cost of lay waste. And trust me dude, when you get in a fight, it won't take you 3 seconds to deplete your mana with defile on active and you spamming that Q's.

Early Game Items:

You might be thinking, i already have a Catalyst the protector and i'm still picking up a Tears of the Goddess? The greater the mana = The more time for you to cast your defile in early game. Karthus is a mana hungry hero so mana items are a real need for him. Plus the great passive of catalyst that let's you have greater lane sustain. But remember, tears first before catalyst. Also, settle with plain boots first because you won't need to upgrade it already in early game.

Mid Game Items:

At this point of the game, you should have at least 300 bonus mana from tears. You will need to have sorcerer's shoes already for you to inflict more damage to your opponents. The catalyst the protector turned into a rod of ages, for that extra ap, health and mana. A great item for Karthus giving him a little tankiness and some good damage. Pick up rod of ages early so that you may have its early passive bonus. After rod of ages you need to have zhonya's hourglass. It is one of the most essential items for Kathus since he is really squishy and you'll be getting the focus in team fights most of the time. But not because i stated that you pick up zhonya's first doesn't mean you have to. Check your tears of the goddess from time to time. When its mana bonus is already at 650+, try picking up Archangel staff first which will then turn into a Seraph's embrace. The unique active of this item is also as effective as the hourglass's. Plus it's stat bonuses and the great passive that turns your max mana into AP. Good choice since you also have rod of ages which gives huge mana. Seraph's or Zhonya's, it will depend unto you which you will pick up next.

Late Game:

Since I already discussed Seraph's, i will now turn to Rabadon's Deathcap. Aaahhh, rabadon, the AP champions' best friend. Now that you have a good amount of ap, you will now need rabadon to max it out. The unique passive of granting 30 percent more ap is really good. I picked this item second to the last since having this item at late game will maximize its passive ap grant.

The Twist:

This is what makes my Guide different from the others, asides the fact that all they want to do is gain kills by killing themselves also. Liandry's torment is a great item for Karthus. Duuuude, at this point of game you'll have 700+ AP. And at this point of game, the opponents have a ton of health. The 2 percent burn from this item plus defile is really a pain in the neck for any hero. Think of it, wiping out a whole team by simply standing in the middle of them in just 10 secs. That would be just great.

WARNING WORDY PART! YOU HAVE BEEN WARNED

This part is to help those who really intends to do great using the champion Karthus. Read patiently, it will help.

In early game, avoid getting involved in team fights since you won't have that much damage output if you have a low level. You'll just deplete your mana pool by turning on defile without even dealing much damage. In early game, all Kathus does is farm. Just farm, farm and farm. Karthus is an item and level dependent champion. He gets real sloppy when he does not have level and has no items. And it's not hard to farm with Karthus thanks to his lay waste and his defile for you to stay longer in lane. Plus that mana bonus from Tears and Catalyst which will let you spam more Q's. When you get to level 6, start to be very observant in the map. See if there will be ongoing fights and contribute damage using your Requiem. I am not telling you to Kill Steal and seriously, avoid kill stealing! Never use your ultimate if you're just aiming to steal a kill from you're ally (Specially when it's only a single champion who is already a sure kill for your allies).

Start ganking at level 7. I am not telling you that you cannot gank before level 7 but i'm telling you to gank at level 7 since at this point, you already have a level 3 lay waste which already deals a good amount of damage. If you have a jungler, ask help from him so that you may get a blue buff regularly. The mana regen and bonus CDR from the buff is a real help for Karthus. Avoid getting over confident with Karthus, one wrong move and you'll be out of the map in split seconds. Also, try practicing that you will hit only a single target with your Q's so that you may have an easy time getting creeps. Karthus is a great farmer since his Q cast range is big. When there are no more creeps in the lane, just go for a quick wolf or ghost in the jungle.

When engaging in team fights, never forget to cast your wall of pain. I've seen ******s who use Wall of Pain in the end, and I'm like, what do you think of your wall of pain, Demacian justice?! A finisher spell?! Continuing, when engaging in team fights, make sure you don't receive all the damage. Your an ap carry, not the tanker. If you get focused, and is receiving a lot of damage already, (and you know that there's no mode of escape already) try getting in the middle of the opponents so that everyone will feel the wrath of your defile and you'll be able to maximize your unique passive, Death Defied! Another tip, avoid using Requiem in the middle of a clash since you'll only get it canceled. There are only a few results in a team fight; either the opponents will all get wiped out or they will flee with low life after the team fight, in this situation, finish them with your ultimate. Another outcome, which might be bad, is that you'll die early. Don't rush using your ultimate. Death defiled is 7 seconds while requiem is only 3 secs. You have 4 secs to cast some Q's and place a wall of pain. The key to maximizing your passive is being CALM. You'll take a second or half to realize your death, so you have 3 or 3.5 secs to do your final damage. Cast 3 q's and place a wall of pain then use your ultimate.

Be mindful of your surroundings, don't use your ultimate every time you die in a team fight, see first if casting your ultimate will turn the tables or just waste 3 minutes for you to be able to cast it again properly. Another tip is NEVER forget to activate your seraph's embrace and zhonya's hourglass. Seraph's embrace first, so that you will be able to maximize it's shield. And when your life drops low, press the zhonya's. Last thing you would like is losing a team fight just becuase you forgot to press some items. So that's it. Your ultimate Karthus guide, but remember, this is just a guide and not the only way to play your champion (But I still believe this will be the best way to win a fight).

VS

OR

OR

ETC.

As we all know, Karthus is a hero who is vulnerable to burst damages. So what to do if ever you get laned to this kind of heroes.

Keep Distance

First thing you must remember is to keep distance so that they won't be able to poke you. If ever they advance and bully you in the lane, be PATIENT. Wait for the creeps to get near the turret. It's better to get denied some experience than get killed just to get some minions. If you think grabbing some minions would get you killed, take some wolves and ghosts first and recall to the base to refill your mana and life.

Wait

If you'll be patient enough, your opponent would just get pissed off and leave you in the lane or use his skills to minions. And when gets too aggresive and dives you to the turret, just use exhaust and the turret will be the one to finish him off. Even if you get killed, there's a high chance that you would kill him also because of your passive Death Defied. Besides, most burst heroes will start to bully you at lvl 6 so take advantage while possible

Don't forget to upvote guys. Sorry for the first boring guide, newbie here. And i'm still trying to figure out how to make those pictures smaller =))) I will continue to work on this, thank you for reading my guide :D If you find errors, don't just go trashtalking, I will greatly appreciate if you point out my flaws so i can improve it :)