Karthus Build Guide by Hullos

I play Karthus, a lot of Karthus. I am no challenger mid player, I got diamond 4 last season with 256 games on Karthus. I was diamond this season but decayed after playing Valorant for 2 months and sit in plat one currently. I have 2.2 million mastery points on Karthus and play way too many normal games for my own good. I may not be able to tell you how to get to challenger, but I might be able to tell you how to build and play Karthus.

KARTHUS NERF

The recent 5% ap ratio buff on Lay Waste was suspected to raise WR by a decent chunk but as it turns out it may have put Karthus right back to one of the best JG and might be looking at a nerf in the near future.

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NEW IETMS AND RUNES

With a new best build being cemented as Liandry's Anguish in basically every case and the recent buff Karthus is in a good spot right now. JG mid and ADC karthus are all solid picks. The runes have shifted a bit and aery in a lane role has become a good pick over Dark Harvest in many cases.

Pros -Versatile builds and play styles -low skill floor and high ceiling -great carry potential -High damage -Great in team fights

Cons -quite a few rough match ups -needs to hit a lot of skill shots -no mobility -little utility

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Tips to keep in mind when learning Karthus

There is no one best build, no build that you will build 100% of the time. People may try to tell you what build is the only good one but they are just wrong. There can be a build you feel most comfortable with and that is fine, but all builds have their uses in certain situations. Karthus is deceptively versatile in builds. I encourage you to play and try different builds. Some of them will surprise you at how well they work. Your play style will change based on build and lane match up. To play Karthus effectively you will have to learn new play styles e.g( poke, aggressive, safe,). Often you will be switching mid game depending on items, levels, and how strong you are. Make sure you don't lose a lead by not adjusting play styles. This will also apply to builds as you might have to shift what you are building to go into a fast Zhonya's Hourglass or Void Staff.

Karthus is not always a "just press R champ" there will be games where your Requiem will be almost useless and you will have to play well with Lay Waste and positioning. Same goes with "abusing passive", don't go flashing in every fight. In reality there are few times where you will need to do that. Often you will be playing like and zone/artillery mage. One of the most important tips is that just starting out you may feel useless outside of pressing Requiem and Death Defied. A lot of the skills you need for playing lane Karthus are gotten from playing him. I cant tell you how to hit Lay Wastes, you learn by playing. Once you start to get good you can start to duel any lane opponent much easier. Also something important is that different people will find different match ups hard, I find Malzahar to be super easy but you may find it hard. My match up list is not the be all end all.

This is the go to rune for your damage centered build, this is most often what you will be using.

This will be ran less with the new Items as with Presence of Mind nerfed manaless builds are basically gone. But will get some use out of people wanting to use DOM/SOC tree build without the need for POM.

While nerfed it is still the best rune in this tree, the healing is a necessity for jg and lane karthus. While Ultimate Hunter is still not as good maybe in the future it come into play.

Many people will argue between witch of the two are better, both are great and help a ton. While Last Stand will often do more dmg, Coup de Grace will allow you to execute low enemy's securing kills. test both out or chose depending on which fits you better. In the end no Karthus rune page will be without one of these.

This is a rune that will change game to game. Gathering Storm is the clear option for scaling into late and will be the pick if you see the game going past 25 minutes. Scorch is for the lane bully, if you are against almost any melee champ this rune can be very helpful in order to prevent engages with poke, assuming you can poke them.

This rune was nerfed hard in the new item update. It no longer gives permanent max mana, but instead mana regen on hitting an opponent. While the mana restor on takedown is still there and still very good the rune is no longer a must have. Though even with tear you might find yourself needing more mana and this is where this rune come into play.

This rune can now patch your mana up a bit if you are taking sorcery tree, a good replacement for new Presence of Mind.

Ability Haste for free is nice and this rune will still be used though the third part of the rune we can not use.

Easy sustain in lane, this rune grants a surprising amount of healing over the duration of the game. The other two in the tree Cheap Shot and Sudden Impact are either not usable or not used enough to consider running.

Pick your poison, all grant you 30 AP, just figure out which one you are going to stack the fastest or most reliably.

This item right now is in a weird spot, it is forced in some builds but kinda sucks. If you take a mana mythic best not start this item.

This item is good for mana and helps you be aggressive in lane Though might present some mana issues if you are not carful. If you starts a mana mythic this is the better choice.

Luden's Tempest, while not bad, is just strictly worse than this item in every case. The only thing this item needs is mana and with Tear of the Goddess as a starting item you can just destroy most squishy targets. Though with a recent nerf and anguish becoming more popular this is only taken into very squishy teams.

While this item did just receive a nerf, it still is a great item for Karthus and the one built most often right now. This item does more DPS than Riftmaker and grants mana along with the %pen. But in addition to that it has a burn effect and more Ability haste. The item is good in any game just only against full squishy teams does this item fall short. Though even in those games this item can do upwards of 15K extra dmg.

This item can work on Karthus but will do by far the lowest dmg out of the three. Its only plus is its sustain due to Liandry's Anguish being a better anti tank item. While sustain is nice karthus even with say Demonic Embrace is not tanky enough to properly use the sustain in most cases and even when you can it would most likely be better just to do the extra dmg. The item is karthus's best safe lane option as the Leeching Leer is a solid early item. I can see the item being used later with some changes but for now the no mana and low ability haste dooms this item into low play rate.

This item is kinda cool but lacks a large enough amount of ability haste and reliable DMG. While it does give you AP for every legendary it still cant compare to the DMG of Night Harvester. The passive while cool is unreliable and only lasts 1.5 seconds so with low ability haste around 1 Lay Waste and that's IF you hit the active.

This item is pretty cool I might even build it... too bad it is a strictly worse Night Harvester in every aspect of the game. Even with the flat pen, it will not do enough extra dmg to overcome the harvesters passive that not only does more DMG than the tempest passive but can proc individually on each champ making it insane how many times you get that extra DMG. Not to mention that with the ability haste on Night Harvester the DPS is higher. While the mana on ludens is nice you would most likely end up building tear anyway so it does not matter when it serves the same purpose. This is only here as riot might nerf the harvester and this could become better.

This item has started to appear as another option for Karthus as a tank route but the item has seen some nerfs. Though in my testing it is not awful if the team needs a tank. You will still do decent late game DMG but in early and mid game you rely on your team to deal DMG so make sure you have some before you build this. I think this build will fall out of favor soon but for now it still sees a tiny bit of play and is kinda fun.

With mana being such a problem this season, Karthus needed something easy to give him mana and this is it. This item is an amazing starting item as it almost singlehandedly solves the mana problem while still offering a very high amount of AP. This will be used in most builds.

This item is why tank karthus is even still a thought but it can still be built in other builds as well. The item is the only good item karthus can build that gives a good amount of HP while also giving AP. On top of that, the burn effect along with Liandry's Anguish can be quite good.

This item got a nice buff to its grievous wounds(GW) effect but in turn lost any reason to build it if you don't want GW. Its component lost the flat pen and so did the item. But for less gold and better GW the item will still be used. Also this item in any of the builds can be replaced with any legendary item.

This item got some small buffs in an extra 10% slow and 50 HP but the extra 400 gold cost and the fact that it no longer combos with liandrys makes it a hard sell. This item I don't see being used almost ever.

This item is basically the same as it was but with 10 ap less and sells for 400 gold cheaper. This item is a must in most builds, at times even first item. The 400 gold less is a great buff to an item that is a must build. Some people say don't build this frankly I don't see why not too.

While I believe the item will still not be used often it did get some small buffs as it costs 500 cheaper and the passive comes back quicker, but in return it lost 10 AP and 15 MR. Maybe build if you really need the spell shield.

While this item did get nerfed, losing 5% extra AP and costing 200 more. it is still Karthus's late game item for big AP numbers. Yes the nerf hurt and all but it will still be used.

This item now costs less and that's great Though with some of the mythic items also offering %pen this might no be as necessary though with the loss of Oblivion Orb's flat pen I suspect it will still see use for squishes. Of course its main purpose is so you can kill tanks so it will be used no mater what.

Builds - lots of words

[*] Night Harvester DH build

The rune page to take is the classic Dark Harvest with precision secondary. You will have Archangel's Staff but even so Presence of Mind is still very helpful as in long fight you will still run out of mana. It also keeps you in lane longer mana wise. Of course the DH proc with Night Harvester is disgusting and can pop ADC's if they are not dead already. The goal for each fight with this build is to kill the squishy targets and that's what this rune page does.

Playing lane

While this is the big DMG build the start of the lane phase will be mostly passive on your part. This is because you are forced to start tear and lose a majority of pressure in lane. Though killing the opponent is not out of the question with some good poke before a fight. At first back hopefully you can buy a Hextech Alternator, this item is great and gives a large spike in kill potential. Keep in mind that you are still squishy and have low HP. This means that while you will mostly be taking Barrier or Exhaust without extra HP from Doran's Ring and the ideal first back item also giving no HP most lane opponents can kill you in the 1v1 if you don't poke well before the engage. You will start to realize that poke is a large part of this build as the passive of Night Harvester provides so much of it. Not only are you just as squishy as before the new items but most other champs also got more DMG. But the same applies to Karthus, this means that it is more important than ever to play like and artillery mage for as long as possible till you actually need to die, of course make sure you die in a useful place. This makes sure that you get the max amount of damage as possible. Abuse the passive of Night Harvester and its movement speed to reposition after a procing it.

When to run this build

This build is nice but even so mainly is only taken when the opponents team has no tanks. It can obliterate squishy targets but fails to do meaningful dmg vs tanks and bruisers. Though in ADC this build becomes a bit more possible as you can guarantee fighting one squishy target.

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[*] Anguish anti-tank DPS (best build ATM)

Due to the nature of this build you will want to be in fights longer to maximize dmg, thus aery does better in this case. Aery also can often out dmg Dark Harvest as well as taking Manaflow Band to prevent needing tear and instead getting Doran's Ring.

Playing lane

One major plus of this build is the fact that you don't get Tear of the Goddess due to manaflow and the mana and anguish. This means that getting Doran's Ring and having aery means you gave a ton of early pressure for poke. While you are still prone to assassins if you poke properly you can prevent the all in. The core of the build is Liandry's Anguish and Demonic Embrace, the two items together grants tons of over time dmg that if play properly can end up doing upwards of 25k dmg together over a game. then paired with hourglass means you can survive dives and stay alive longer plus becoming even more tanky with demonic' s passive. Then finally with the anguish passive and a potential Void Staff you can deal with tanks great you might even have room for a deathcap if you don't need anti heal. The main weakness though is the lack of sustain without Ravenous Hunter. Doran's Ring does a serviceable job in lane but late game it can become a bit problematic HP wise. That is why it is even more necessary to play back and safe to maximize dmg till the time is right to die.

When to run this build

This build is now the best build for lane and JG (jg taking DH though). It works in any scenario against any team. Only Night Harvester when into an entire no tank team can outperform it. The lots of dmg along with antitank mana and solid ability haste makes this build the way to go.

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[*] RiftMaker Sustain

Dark Harvest in an attempt to make up for the loss in DMG with this build and Ravenous Hunter to add on more omnivamp. Just the basic rune page lines up well though sorcery could be taken to use Absolute Focus and another dmg amp rune although Manaflow Band would most likely be useful as karthus might need more mana than tear can provide at some points with this build.

Playing lane

This build in fact has less DMG than most previous karthus builds with old items and on top of that less healing even with the omnivamp from Riftmaker. While it can be nice in lane as a first back item Leeching Leer the lack of ability haste makes it have a TON less DPS than other builds. This means that other builds due to increased DMG might out heal this build just with Ravenous Hunter. While the passive is cool, surviving to have it at max stacks is difficult (that's part of the reason demonic embrace is part of the build so the burn keeps you in combat). Even the true damage is lack luster without the dmg to back it up with such low ability haste. You could take Cosmic Drive to mend that problem and get some MS but to build another item just to make ends meet is not ideal. The upsides for this build is that in lane it is the safest build with the most sustain. Thus being the safest lane you can take Teleport and not get killed. Also with the Liandry's Anguish nerf it now has higher %pen for later in the game, but it still takes forever. The last good thing I can think of is that this item would feel solid into assassins and other bad matchups like Vladimir. Beyond that this build will be mediocre until maybe a tested tank karthus comes to fruition.

When to run this build

This can be taken into tanks but even then Liandry's Anguish is still better. But the main thing to take this item into is into unfavorable matchups like I said Vladimir and Kassadin. The build helps you survive into assassins matchups but does not help you deal DMG later, you will be better off building Seeker's Armguard.

TOP LANE KARTHUS

Top lane is the least played role for Karthus, that he can be played in, and for a few reasons. Now more than ever with ROA gone, top lane becomes more difficult to play. Even if you take the new Leeching Leer you still will not have the DMG needed to play late game. Even with that item, without Barrier or Exhaust you still might get destroyed if you don't position perfectly. Not to mention most likely you will be fighting some heavy engage bruiser that Karthus struggles so much against. With Tanks, being Karthus's best top lane matchup most times, becoming stronger, them now being able to kill you, that only leaves ranged top lanners as a safe pick to play karthus into. At the end of the day never pick karthus top blind.

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ADC KARTHUS

ADC Karthus on the other hand is almost if not just as viable as mid Karthus. Having a support can solve a lot of problems for Karthus and help him make use of early game Lay Waste damage. Though the supports that go well with Karthus are limited, most of them are listed in the synergies tab, they work incredibly. The average shield/heal Support like Lulu is far from the best choice to run with Karthus. But any engage support will work wonders, the best being Leona, Thresh and Nautilus. Most of the time assuming you have a good support, you will build the Dark Harvest Night Harvester build to play aggro in lane. Very rarely will you be playing safe in bot lane unless they pick Lucian Leona or something even more aggro than your lane. Starting the new Tear of the Goddess means that even with an aggressive support you may find it more difficult to dominate bot lane. There is also the problem that since you are behind on levels and Karthus relies heavily on ability damage you will do slightly less damages than normal.

Pointers on playing late game

While yes Karthus is a late game champion, but he is not as strong as many think. By the time late game rolls around yes you may have 1000 AP, depending on the build, but everyone in the game will almost certainly have a way to survive your Requiem. Weather that be a Zhonya's Hourglass of their own, the supports heals/shields are just as strong as Requiem or they are just a lot more tanky than mid game. Not to mention the countless other ability's. You will start to see that unless you play like a god, you will almost never have enough damage to carry hyper late game as it becomes harder to get the damage off. Keep this in mind going into the next point.

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Late game means that inevitably, there will be a lot of team fights. In team fights too many new Karthus player think the right play is always run in like a madman with Defile on and die, this is not the correct play style for late game. Yes there will be times where that is the correct play, but it does not happen often and most certainly not every team fight. I cant really describe when to flash in and die, but a lot of factors come into play, to name a few: has someone else engaged? How many people are close together? Can the team follow up? Can the enemy team get away? Do you have Zhonya's Hourglass up? Instead of going for the all in play all the time, play more like an artillery mage to maximize you dmg and act like a final line of defense for the ADC.

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While in mid game you may have been able to kill anyone you wanted, especially when you are strong, but in late game prioritizing the correct targets is essential. Even if you are late game you will do meaningless dmg to the full tank Dr. Mundo. Since you play like and artillery mage you can aim for the ADC, or other high dmg targets, and with Wall of Pain potentially catch them out. Even when you flash in make sure you are going for the highest threat target. This should be done at all points in the game but becomes even more crucial at late game.

IM KEEPING THIS HERE JUST IN CASE RIOT RE-DOES EVERYTHING SO I DONT HAVE TO RE-WRITE IT.

The main item for mages, and while this item is very good on Karthus for just doing lots of damage we have other options as well. This item grants mana damage and gets you to the minimum 20% CDR necessary for Karthus. You will be taking Dark Harvest with this item almost every time.

This item on paper seems insane on Karthus, and it is good, it is not as good as people lay it out to be, at least not on its own. This item is for when you are going to play safe and sustain in lane. But even though it grants HP Health and mana, it grants no CDR and not enough dmg. That's why this item is almost always paired with Archangel's Staff this item fixes all the problems of ROA. The only downside being it delays the power spike so the build is only used when you know you will get to late game.

This item is often paired with Rod of Ages, but can be build on its own to hit a smaller power spike earlier, often allowing you to build Liandry's Anguish second item.

This item is incredibly strong on Karthus and would be put into almost any build, the only thing stopping it being it offers no CDR and no mana. but many builds such as Archangel's Staff rush and the no mana item build seek to solve those problems to use this item, that's how good it it.

basically the only boot you will ever buy unless you are going the tank-ish build. Great magic pen and a great early buy.

This item is built in most builds in one way or another as magic penetration is very good. One key thing is that if the enemy team does not have heavy healing, it it a better idea just to keep the Oblivion Orb and go to the next item.

Obviously a great item, you build it almost every game in almost every build. The item's synergy with Defile is just great as well as you can throw a Lay Waste right before you activate this item and it will go off when you are in stasis. Of course preventing people from diving on top of you is always great. This item can be build at any point in a build depending on how badly its needed.

This item is good into certain teams and when in combination with Liandry's Anguish can be quite devastating for catching people out or in a team fight. Though I would only recomend against teams with low mobility, and at least a tank or two to get value out of the item otherwise its better to just go into Void Staff or Rabadon's Deathcap.

This item is of course the big damage item, and will be in almost every build even if its replacing boots. Though many players get the item too early, this is a late game item and should only be bought no earlier than 4th item. or else you risk losing your lead or falling behind further as its benefits are less are less the faster you get it.

This item is amazing and built again in almost every build. The only time this is not a good item is if the enemy team has no tanks or even bruisers.

I build the item very rarely and only if the spell shield will be benificail. In almost all other cases Abyssal Mask is better.

This item is used most often in hyper late game to replace boots as your sixth item. The item grants movement speed to compensate for boots and a nice passive to get out or get in to a fight, or just to pop the ADC. Solid item but almost never build other than 6th item.

This item has recently risen in popularity, it has its upsides in certain match ups and can help you dominate a lane even more with better engage. The active is also nice in team fights if you can land it on multiple targets. It would only be built to replace Luden's Tempest but works well.

Both are somewhat meme items but do have their uses. Frozen Heart can be built in with Archangel's Staff for the clean 40% CDR and Sunfire Aegis while you cant proc the passive, it is the best armor item for Karthus that offers HP.

Builds - lots of words

[*] No mana item build

I have mentioned this build many time so far in the guide, the reason being I believe it is one of the best and most consistent builds, while still being versatile. The name makes it obvious but you don't build a single mana item beyond occasionally Dark Seal. The mana all comes from runes like Presence of Mind and Manaflow Band. then in order to deal with CDR you take Transcendence and the 1-10% CDR rune. With mana and CDR covered you can build Oblivion Orb, Sorcerer's Shoes into Liandry's Anguish. these three items create a massive amount of power that spikes faster than Tear of the Goddess for the same gold and keeps kill potential in lane with double pen items. The power though does not fall off and only opens paths for almost any other item needed. this build allows for you to get to necessary items like Zhonya's Hourglass or Void Staff faster. You have the option between Barrier and Exhaust depending on lane opponent.

The rune page you will be using is the second rune page on this guide with Summon Aery, making any personal changes depending on match up. this of course is used for the CDR and mana but also grants a large amount of poke for tough match ups with Summon Aery

Playing lane

Corrupting Potion is the main starting item, or Dark Seal, Refillable Potion. This start mends the lack of sustain the build has health wise. with Ravenous Hunter out you need to start this in order to stay in lane and out poke the opponent. That's how you play lane phase for this build, poke until they cannot engage or till you can engage to win the 1v1. mana early can at times be hard to manage but that becomes better the more you play Karthus and the better you become at farming. DON'T JUST SPAM Lay Waste ON THE WAVE EARLY. punish the opponent for walking up to farm and if they don't need to walk up to farm keep a watch for misplays in positioning, you may be good at poking opponents down but a Wall of Pain with a few Lay Waste's is very possible. With this build once you get ahead you can start to be more aggressive with mana once the runes get stacked, thus playing more aggressively, throwing more Lay Waste's at the opponent, hard shoving or keeping the opponent off the wave.

When to run this build

This build is good against everything to some degree, the main thing this build should not be used against is easy match ups. if you are super confident in lane that you can kill the enemy champion this build is not ideal, but since Karthus does have a lot of bad and even match ups this build exists.

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[*] Classic DH luden's

Speaking of ideal verses favorable match ups, this is the build. The items them selves don't look all too different but the runes make all the difference along with Luden's Tempest. With this build you aim to get as strong in lane as fast as possible, even if you die to get the kill, you turn into a weird looking burst artillery mage. with features of both. with Luden's Tempest covering CDR and mana along with Presence of Mind, and Ravenous Hunter with Taste of Blood covering sustain you have all the pieces to need in one item. This build will suffer when against lots of tanks as you may not have the HP or defensive items to live verses them or the damage to kill them, usually you will end up lacking one or the other. But what it does do is one shot the squishy targets and put them to basically half hp at all times with Requiem if you get strong. This build is high risk high reward and creates the Karthus stereotype where he only need to press R.

The rune page you will be using is the first rune page on this guide with Dark Harvest, This is big damage, the pop the enemy ADC in one Lay Waste rune. Aggressive plays and 1v1's are the name of the game with this rune page.

Playing lane

Starting with Doran's Ring you can immediately start bullying your lane opponent with Lay Waste assuming you took this build into a winning match up. Their CD's will often be much higher than yours enabling you to punish for any missed skill shots with Wall of Pain. This only get better as lane goes on as you get more mana And eventual they will not even be able to stay under tower from the barrage of Lay Waste's. The main thing to worry about is of course the jungler, as if you play aggressive as an immobile mage you are bound to get ganked. Depending on the enemy JG, if they don't have a good gap closer and with a good dodge or two of a skill shot a 2v1 is not hard. Just target the likely not full health Jungler as they approach with Lay Waste and you can easily finish them off by the time they get to you. Make sure to kite away between Lay Waste's as that is one of the most important skills on Karthus. This may be the big damage low brain power build but do not fall into the trap that is Flash inting. Many new Karthus players Flash in to "abuse" passive but proceed to miss everything and die. Over time you will start to see the correct time to Flash in. The most often time to do it is when the opponent is doing baron and you need to stop it. Play like an artillery mage for most of fights until the time is right to go in with Defile on. you are back line but still you should die before the ADC unless they are useless. most likely take Exhaust allowing easier 2v1 and better kill potential with the slow.

When to run this build

I said this before but run this into any wining match up or squishy enemy team. This build is also the best to start with as a new Karthus player. simple play style and still useful late even when behind. This build can also be altered to an extent to work decently in most cases.

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[*] Scaling late game build

This build is the most simple to play as it revolves around playing safe and farming for late. The main two items being Rod of Ages and Archangel's Staff and getting them stacked. Of course Karthus stacks them fast but even so the power spike is still late. Of course you can go into any item after the first two as well, making it versatile. You can use almost any kind of rune page and can play how you want late game as long as you play safe early. This build makes killing potential in lane almost zero with first items being Tear of the Goddess and Catalyst of Aeons. With no mana problems you can farm forever you will and probably take Teleport for a better scaling experience. This build has the highest AP of all the builds for late game but the worst early even early-mid game out of any of them.

Both rune pages can work for this build, both provide Presence of Mind. The main difference being do you want more sustain and some late game burst of Dark Harvest rune page or the poke and scaling of the Summon Aery rune page. Honestly this is based on preference and what you are more comfortable with.

Playing lane

The most simple lane phase to play, farm and play back. The likelihood of you killing you opponent is very low and the champions that you play this build into you will not want to try to kill the opponent as it will not end well. Ad for starting items, it depends of what rune page you took, if you took Ravenous Hunter then Doran's Ring is the best option. If you did not take it then Corrupting Potion is most likely the pick. A jungle gank can help you get to late game faster as can a lucky Requiem so keep watch for them at all times. This build will out scale or allow you to scale with them so not dying in laneing phase is essential.

When to run this build

As I said before, this is for out scaling or scaling with the lane opponent namely the two big problems being Kassadin and Vladimir two very hard match ups but this build gives you a chance. other times that you can build this is when you don't have much kill potential on either side of the lane such as Ryze.

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