Hello everyone my name is DRAFTINGBOY123. I have been a LoL player for almost a year now and it has been one of my favourite games. I just recently switched to the Garena server from the US server in order to get a feel of another environment. I'm pretty new here to mobafire since I spent most of my time on leaguecraft but I found a lot of good guides here so I decided to share what I know. Well, back to business.

Karthus is a very powerful champion if played correctly. Contradicting to other people's beliefs, He is not an OP champion. He is actually quite balanced. By experience, the number of kills you get will not be too far from the number of deaths you will receive. That is if your a team player. Greedy Karthus summoners tend to get an amazing no. of kills but it will also come with underfed team mates and a high risk of losing. Remember the goal of the game is to destroy the opposing nexus but it's purpose is to have fun :).

This guide aims to promote Kathus's strengths and cover his weaknesses since you are only as strong as your weakest link. The end-product of this build will be a healthy Karthus with an incredible amount of mana and ability power. Detailed stats shown above and may increase with varying runes and masteries. Note: The AP shown is only the least possible you can get. It doesn't show the bonus AP gained from your Items' effects. Same applies to mana

Please take the time to read and understand the full guide in order to bring out it's full potential.

The chapters here will cover the General info. Skill Builds, Item Builds, what you should know if your here to skim.

Pros:
- Great harasser (One of the best in-game)
- Incredible killer and high damage support
- Fanstastic slow (80% at max + magic resist and armor reduction)
- Great farmer and pusher
- Amazing AoE and nuke
- Ultimate can benefit you and the team
- Helpful innate
- Fun to play :D

Cons:
- Squishy (However, my item build tries to cover that)
- Focused on
- Ultimate can be countered in a couple of ways
- Can run out of mana early game if your too reckless
- Can be out harassed if you can't place Lay Waste to your advantage
- Hard to master, if you feed early game then be sure to find a way to cope up because if you don't then you definitely will be the gold mine of the other team

- Death Defiled

(Innate): Upon dying, Karthus enters a spirit form allowing him to continue casting spells for 8 seconds. During this time his abilities cost no mana. His death timer is also reduced by 20%.

This is a nice passive that allows you to deal damage beyond the grave. Use this to your advantage if you ever die. Especially in a team fight.
- Lay Waste

(Active): Creates a delayed blast at Karthus' cursor position. After 0.5 seconds, deals magic damage to each nearby enemy; damage is doubled if it hits only a single unit.
Cooldown: 1 second.
Range: 875.
Area of Effect: 200. Cost: 20 / 26 / 32 / 38 / 44 mana.
Magic Damage: 40 / 60 / 80 / 100 / 120 (+0.35 per ability power).
Cooldown 1 seconds | Cost 20 / 28 / 36 / 44 / 52 mana | Range 875

This shall be your farming and harassing skill. If you can place it properly, it deals an enormous amount of damage. In a team fight, try to hit one opponent at a time so that it'll trigger the double damage feature. By experience, this can wipe out the opponent team faster.
- Wall of Pain

(Active): Karthus creates a wall between 2 obelisks at target position. Any enemy passing this wall have their armor, magic resistance, and movement speed reduced for 5 seconds. The wall lasts 7 seconds.
Cost: 100 mana.
Cooldown: 18 seconds.
Range: 1,000. Wall Width: 800 / 900 / 1,000 / 1,100 / 1,200 .
Armor & Magic Resist Reduction: 15 / 20 / 25 / 30 / 35 .
Slow: 40 / 50 / 60 / 70 / 80 %.

This is an amazing and very versatile spell. It severely slows the enemy and deducts their armor and magic resist. It also gives vision so use it to scout possible ganking areas and brushes. Opponents usually refrain from passing it so you can use this to your advantage.
- Defile

(Toggle) - Off: Karthus steals energy from his victims, gaining mana on each kill.
On: Defile drains Karthus' mana to deal damage to nearby enemies each second.
Cooldown: 0.5 seconds.
Area of Effect: 450. Mana Gained: 20 / 27 / 34 / 41 / 48 per kill.
Cost: 30 / 42 / 54 / 66 / 78 Mana per second.
Magic Damage: 30 / 50 / 70 / 90 / 110 (+0.25 per ability power) per second.

This is a nice AoE spell that can deal a lot of damage with the items I presented. Refrain from using it at earlier levels since it's not mana-effective at those times. This spell helps a lot in teamfights and 1 on 1. If you've ever met champions that can do backbreaking and confusing moves (blinking around you or running in random places around you to avoid damage or stall). It WILL prove their efforts useless since they're going to have to be in your range to do it.
- Requiem

(Active): After channeling for 3 seconds, Karthus deals magic damage to all enemy champions.
Range: Global. Cost: 150 / 175 / 200 mana.
Cooldown: 180 / 150 / 120 seconds.
Magic Damage: 250 / 400 / 550 (+0.7 per ability power).

Ask your allies to help point out when you should use Requiem to get kills in different lanes, or alternatively, alert your teammates when you are about to use it. However, be sure to keep your eye out for action elsewhere on the map; you may be able to help someone when they otherwise wouldn't have time to type for help.

Before using Requiem to kill a retreating enemy, consider the shield/heal/defensive abilities and items of the enemy team; at endgame, it is usually more important to have an ultimate up than to force enemies to heal.

Be sure that whenever you use Requiem, it helps you or the team since it has one of the longest cooldown in the game. Also take note of items and abilities that can block or reduce the damage of Requiem such as Banshee's Veil, Hex Drinker, Sanguine pool etc....

Start off with a Meki Pendant or Sapphire Crystal,depends if you prefer mana or mana regen, 2 health potions and farm as much as you can. The mana these items will give shall support your Lay Waste.
On your first recall buy a Tear of the Goddess since you will be spamming your Lay Waste a lot therefore giving you an early start on your mana pool expansion and Boots if you have the money.
Next buy Boots if you haven't yet and a Ruby Crystal for the HP. Cover your squishiness by expanding your HP
Next, complete your Catalyst the Protector and then your Sorcerer's Shoes. This will give you Spell Penetration and more HP/MP
Finish Rod of Ages and start creating your Rabadon's Deathcap. Let RoA charge and start working on your AP
Once that's through finish Archangel's Staff.

At this point you should have already 500+ AP. The items your going to buy at this point should be built to help you in-game.

If you need more survivability (which is usually the case at this point), take Rylai's Crystal Scepter. It gives a nice amount of HP without sacrificing Ability Power. It also has a nice slow on top of it.

If you need more AP, take Zhonya's Hourglass. It gives a nice AP boost plus an awesome active.

If you need Magic Penetration, take Void Staff or Abyssal Mask. Void Staff if they're a Magic Resistance heavy team or Abyssal Mask if you have more than 3 AP Champions in your team and they're not stacking that much MR.

If the game still persists at this point, Choose Guardian Angel if you want survivability or another Archangel's Staff for more firepower. Your MP is going to be around 4000+ at this point so you'll gain around 266 more AP with this item alone.

I take 9/0/21 masteries in order to utilize the summoner skills as much as needed. You can take other masteries such as 21/0/9 to bring out his damage potential to the fullest. Depends on you really.

This Mastery page really helps since it decreases the total cooldown of your summoner skills. One clear advantage I found was the incredibly short time that you spend when your dead. Karthus's innate already grants him 20% less time dead, add that to the 9.99% reduction you get by following it. Death for you will be less of a problem than it already is.

Your rune page relies on your masteries and play style. With the masteries presented, use the standard cookie-cutter mage build. You can try out different runes and tell me what work out best so I can improve this guide. Of course your help will also be honored :).

I believe this guide by Searz can help Rune tips - What Secondary and Primary means and more.

If you don't know the standard mage build. Then I'll elaborate.

Greater Mark of Insight (9) for the Spell Penetration

Greater Seal of Clarity (9) for the Mana Regeneration

Greater Glyph of Focus (9) for the Cooldown Reduction

Greater Quintessence of Fortitude (3) for the Health

I get

and

Reasons:

Flash
- It is a great escape spell
- It allows you to catch up with enemies who are not in your spells range
- Allows you to escape annoying AoE Spells such as Crowstorm and Dark Binding
- You can use it to jump in with the team right before a teamfight
- You can use it to place yourself during a teamfight

Clairvoyance
- It gives me more map control
- You can use it to scout brushes anywhere in the map (helpful during the start of the game)
- Allows you to check a fleeing foes HP
- Allows you to spot ganks before they even come
- Allows you to check which lanes are their champs going at the very start of a game.

However if your staring out with Karthus or dislike Clairvoyance, you can switch it with another spell such as

or

Ghost can help you flee away or catchup to enemies and Exhaust gives you another slow to your arsenal plus it gives you a weapon against pesky DPS champions.

The chapters here will cover tips and techniques with Karthus. Read it of you have the time and if you want to be able to play Karthus more effectively and efficiently.

Your first items should be able to keep your mana up for those Lay Wastes. The mana cost of that spell is quite minimal but keep in mind that strength comes in numbers. With all that spamming comes the huge mana demand. So practice this. At earlier levels, use your Lay Waste to last hit instead of take the minions' whole health bar. Since it's an AoE you can last hit multiple minions at the same time. During these levels, focus on the minions that your minions are attacking. This'll save you much more mana though don't expect to last hit like a pro right away. Your going to have to practice unless your a pro already. This will allow you kill all the minions in that wave while using very little mana thus putting you in a nice advantage.

Once you get your Tear of the Goddess you can spam your Lay Wastes much more. With the runes and masteries I gave you, You can spam it like there's no tomorrow. You will now be able to harass your opponent without worrying about your mana too much and kill minions at the same time with around 3 or 4 Lay Wastes. Bear in mind that if you get Defile first, you will access it's mana gaining passive but don't rely on this too much since it gives as much mana as Lay Waste at it's level costs.

Since you are a mage your going to have to stay at the back. Lay Waste them and if they get close enough Defile. If ever one of them strays too far away from his/her teammates. Wall of Pain them (if it's up), Defile, and Lay Waste like there's no tomorrow. They're going to get double damage from Lay Waste since they're only one target. This is usually an ensured kill since your teammates are going to help you kill him and if they don't they still have to go through all that Lay Waste and Defile damage so they should hope they survive.

If your confident that your team can cover for you then go in closer that your Defile can hit all of them. Spam your Lay Waste as usual but try to go for the nuke damage instead of the AoE since the damage difference can help you wipe out the opposing team faster.

If you ever die during a team fight. Don't fret, you still have 10 seconds to aid your team and if they're smart they'll keep the opposing team in your zone of influence. Turn Defile on, spam Lay Waste. Wall of Pain and Requiem if needed. When your timer's up. Your going to spend a short time dead so you can go back into battle if it's still going on.

What other people don't see with Karthus is that he is actually a good initiator of team fights. He has 2 skills that can initiate if used wisely. Wall of Pain and Requiem. Wall of Pain is pretty obvious since landing one on them will result in an EPIC slow and magic resist + armor reduction thus putting your team in a HUGE advantage. Plant it, jump in at the same time and DOMINATE that other team. The other skill is Requiem, though at first glance you may think that using it would be a waste but it's not. That is if you use it properly. Make sure you and your team are together. Tell them you'll initiate with Requiem so that communication can be established. Activate your skill and as soon as the damage hits and your channeling stops. You and your team jump in and DOMINATE. The other team will be at a HUGE HP disadvantage. Though if you do this make sure you'll kill as much of them (if not all) as you can. You won't have your ult to finish off anyone running. To be on the safe side, when you jump in, place your Wall of Pain immediately. This'll slow all of them and decrease their magic resistance and armor thus having them receive more damage. You can also save it so that you can use it later on to chase down any survivor.

Note that this technique is rarely used so the opposing team won't have a clue that your initiating thus giving your team the element of surprise.

With this build I have given you another technique. If you took Zhonya's Hourglass then surely you'll remember it's active. It synergizes very well with Karthus's Defile. Go in when the team is fighting. activate Defile and wait for the right moment. When it comes, Place a Wall of Pain so that it hits as much of them as possible, go to them then activate Zhonya's active. This time you won't be relying on Wall of Pain's slow rather it's Armor and Magic resistance reduction. So you should never be using this to chase. Use it during the battle to out-damage the other team.

Though you can also adapt it so that it fits the moment. For example, if you team is focusing you. Defile then activate Zhonya's. This'll make their efforts useless and giving your team a 2 second moment to counter attack. By then, The opposing tem should have been exposed to your Defile's damage and if your lucky enough skills that could finish you in seconds (such as Primordial Burst and Crowstorm). Don't be surprised if that happens. Champs such as Veigar tend to one-hit Ult high AP users to quickly finish them off.

Wall of Pain is a very versatile spell. It has other uses other than the slow and armor + magic resist reduction. When you check a brush, plant one since it gives vision. When you attack a turret, plant one at the area they are most likely to gank (usually one that makes sure you can't escape). If you are not to initiate a team fight/Your team is incomplete, plant one directly between your team and the other. Based on experience, Wall of Pain gives a psychological effect on the opposing team. They will refrain from passing that wall unless they become too impatient and make a mistake by passing it. This'll allow you to kill him/her.

If ever you find yourself the focus in every team fight of your game where your teammates will just forget you when your being focused then there's one method still available. Suicide Bombing. Use this only when you don't last around 3 seconds in a team fight. Go in the middle of the battle (preferably closer to the enemy team), activate Defile, Wall of Pain and Lay Waste all of them. Your going to die in about 3 seconds since your the one nearest to them. When you die keep on casting your spells. They will be in range of you already and you still have your team to dish out some damage so you'll still prove your worth in the fight.

Karthus is an amazing champion that can dish out high damage, and give high damage support. He can finish off anyone who runs ensuring no escape. Be creative with him and you'll acheive amazing results. Follow what I said and your opponents will be watching out for you. One wrong move and they'll end up dead. With you as the high priest leading their Requiem.

This guide is still incomplete but I thought it had enough info to share so I'll still add more very soon.

Please vote and comment. They are highly appreciated :D