Hello there, my name is xJappa and I stream on twitch.tv/xJappa. I am a Grandmaster Karthus botlane OTP on EUW. I have played over 1000 games on Karthus this season alone, so I feel like I am qualified to write a guide. Another reason for me putting together a guide is to help my fellow summoners (especially ADC mains) who have been stuck in ranked.

If u have any more questions make sure to stop by to my stream, i will gladly answer them! I stream every day!

If you decide to play Karthus bot lane, there's a bit of a learning curve. Karthus has a very different playstyle compared to "normal" ADC's. If you die on a traditional ADC, it's very bad. Dying on Karthus isn't that big of a deal, some teamfights it's even optimal to die. If you die on Karthus you still have the ability to farm a wave, get a Dark Harvest stack or even a kill (or more).

The more you'll play Karthus, the easier it'll become to hit your Lay Waste.

On your first recall you ideally want a Lost Chapter. If you don't have 1300 gold on your first back, you can purchase one or two Amplifying Tome's. If you play against a lane which is very skillshot heavy, such as Ezreal/ Karma, you can purchase a pair of Boots to make dodging skillshots easier. If you have an extra 350 gold in your inventory laying around, it's always a good idea to purchase a Dark Seal. It's a very cheap item and makes snowballing a lead easier. Some people like buying Sorcerer's Shoes if they have 1100 gold exactly on their first recall, I rarely do this (it all comes down to personal preference).

Items

Karthus - Full Damage Build If you're the only AP member on the team and the enemy team is squishy Blackfire Torch and Sorcerer's Shoes will always be part of your core build on Karthus. If you're solo AP or you feel like the enemy team isn't building any MR (magic resistance) you can buy a Stormsurge as your third item, this is usually your most solid option for maximum damage. If you feel like the enemy team is stacking a lot of MR it's smart to buy a Void Staff as your fifth item. If they start building MR after you're done building your Stormsurge, it's adviseable to purchase a Void Staff after your Stormsurge. It's best to purchase a Rabadon's Deathcap as your fourth or fifth item, depending on the state of the game (which comes down to if you need a Void Staff or not). It's also possible to purchase a Zhonya's Hourglass if the enemy team is non-stop diving you. A Zhonya's Hourglass is very good on Karthus since he can keep his Defile (E) on while in Zhonya's Hourglass. You always want to activate your Zhonya's Hourglass when you're close to dying and in the middle of the enemy team so they're all taking damage from your Defile (E) and Liandry's Torment (you also do more damage the lower health you are because of your Last Stand rune). You purchase Morellonomicon or just an Oblivion Orb if your team needs healing reduction.

Items

Karthus - Utility Build You go utility Karthus when you're against a short range / hard engage enemy team Blackfire Torch and Sorcerer's Shoes will always be part of your core build on Karthus. When you're playing Karthus vs HP stackers you always build Liandry's Torment second. When you purchase the Liandry's Torment, make sure you never purchase the Fated Ashes. You want to purchase the Haunting Guise first and only purchase the Fated Ashes last before completing the full item. Nine out of ten times the enemy team will have some form of MR (magic resistance), so you'll want to purchase a Void Staff as your fourth or fifth item. After you purchase your Void Staff you'll want to purchase a Rabadon's Deathcap unless a Zhonya's Hourglass has insane value. With these last two items you'll just have to look at the state of the game and see what you and your team needs. If the enemy team builds MR, you go Void Staff (which is almost always the case). If you want damage, you go Rabadon's Deathcap. If you want an extra defensive item because the whole enemy team is diving and focussing you, you can go Zhonya's Hourglass.

Every laning phase is different depending on the matchup, but generally you want to play as aggressive as possible. This doesn't mean that you have to take every fight like a maniac, you'll have to be a little (just a little bit) smart about the fights you take. Pushing in the enemy bot lane while poking them down with your Lay Waste is a very good strategy. Getting them low means you get Dark Harvest stacks, which are very valuable on Karthus.

While you're pushing in the enemy bot lane, you should always be aware of the enemy jungler ganking you. This is good for solo queue because if the enemy jungler is ganking you he is not ganking your teammates, which can get them ahead and as long as you don't die from the ganks you should be way more ahead than your enemies as a team.

Even if you die as Karthus during laning phase, it's nowhere near as bad as a regular ADC dying during laning phase. Thanks to his passive ( Death Defied), Karthus is still able to farm a wave, get a Dark Harvest stack or even a kill (or more) while dead.

The hardest part about Karthus (in my humble opinion) is hitting his Q ( Lay Waste), this will take some getting used to as a brand new Karthus player. As soon as you hit level six you want to make sure to keep checking top, mid and jungle to see if you can help you or your teammates get a kill with your R ( Requiem).

SUMMONER SPELLS - FLASH: Since I mostly played traditional ADC's (Attack Damage Carry) such as Jhin, it took me a while to understand that it's really good to aggressively Flash in as Karthus. If flashing in means you die, but you get a kill, it's almost always worth it. This means you'll be getting a kill, a Dark Harvest stack, a potential wave and possibly even another kill with your Requiem (or more kills). But if need be, you can always Flash away too. SMITE: You always want to take Exhaust as Karthus bot lane. Exhausting an enemy, paired with your Wall of Pain, slows the opponent down tremendously. This makes hitting your Lay Waste easier. Since you want to play very aggressively during laning phase, Exhaust will help you win the fights instead of e.g. Heal or Teleport. Exhaust is also really useful against burst damage since it'll give you more time to live. You can use this time to run, or to play aggressively and fight.

Death Defied: Upon dying, Karthus enters a spirit form that allows him to continue casting spells. What makes Karthus so strong in the bot lane is his passive Death Defied. Dying on a traditional ADC could prove catastrophic, it isn't that big of a deal for Karthus. When Karthus dies, he can still farm a wave, get a Dark Harvest stack or even a kill (or more than one kill). Dying as Karthus during a mid/late game teamfight could actually be game changing if the enemy team is forced to fight on your passive while they take damage. Lay Waste: Karthus unleashes a delayed blast at a location, dealing damage to nearby enemies. Deals increased damage to isolated enemies. By far the hardest part about Karthus, this will take time and practice to fully master. Finding out what dodge paterns most players use and capitalizing on them is something that takes time. Something most players don't know is that Karthus Q ( Lay Waste) does more damage on isolated targets. Wall of Pain: Karthus creates a passable screen of leeching energy. Any enemy units that walk through the screen have their Move Speed and Magic Resist reduced for a period. You always want to start of a fight with your Wall of Pain, it slows enemies which makes them easier to hit with Lay Waste. If you Exhaust and Wall of Pain an enemy they are barely able to move which makes it easier to land skillshots. The edges of Wall of Pain also give vision to unwarded bushes. Defile: Karthus passively steals energy from his victims, gaining Mana on each kill. Alternatively, Karthus can surround himself in the souls of his prey, dealing damage to nearby enemies, but quickly draining his own Mana. If you're going all-in during a fight you want your opponent(s) to stand in your Defile, this is especially good if you have a Liandry's Torment. And thanks to Last Stand you'll deal more damage the lower health you are. Defile also makes it so last hitting minions, jungle camps, and champions gives you Mana back. Requiem: After channeling for 3 seconds, Karthus deals damage to all enemy champions. Requiem, also referred to as an outplay button (sarcastically), is an extremely powerful ability. You'll have to be mindful of a couple things though, if the enemy team is able to stop your R ( Requiem) with CC (for example, Blitzcranck's Rocket Grab). If the enemy team has an ultimate ability such as Zilean's Chronoshift. And finally, if the person you're about to Requiem has a Stopwatch in their pocket.

KEYSTONE Dark Harvest: Getting a Dark Harvest stack on Karthus is extremely valuable. A kill and a Dark Harvest stack is always worth it (unless you have a big bounty on you). If you end up getting the Dark Harvest stack but not a kill, it's not the end of the world since you might still be able to get a wave as well. But theoretically speaking, dying for a Dark Harvest stack shouldn't be your goal, it should always be getting a kill plus the Dark Harvest stack. Using your Requiem for just a Dark Harvest stack isn't worth it as well. You should always be aiming for the kill. Since you'll be playing very aggressively, you'll be getting a lot of Dark Harvest stacks, which makes you scale better and do more damage. MAJOR RUNE Ultimate Hunter: This part is rather straightforward, Ultimate Hunter makes it so Requiem goes on a lower cooldown. During mid/late game, your biggest threat is your Requiem. Thanks to Ultimate Hunter it'll be availble more often. MINOR RUNE Last Stand: The Last Stand rune synergises extremely well with Death Defied ( Karthus passive). Last Stand makes it so you deal 11% increased damage to champions while you are in Death Defied. It basically means you'll be doing more damage, which is good.

Thank you so much for reading my Karthus guide, I put a lot of effort into it and I hope it helped you out! If you have any questions or notes regarding the guide, or if you just want to say hello, I stream every day on twitch.tv/xJappa. I usually stream around 8 p.m. CET, so you'll be able to catch me then! I stream in English and I always try to read chat whenever I can. I hope you enjoyed this guide and will refer this to your friends and fellow gamers looking for tips & tricks. You can also ask question on Twitter or the Mobafire comment section, I'll do whatever I can to answer any questions. I know League of Legends can be frustrating at times, but hopefully you'll be able to climb by following this Karthus guide! -xJappa