This is a guide designed to mess with people.. please note this will not always work, as the team composition isn't THAT great because of the squishyness... but we can make do, and if you have good players, you will be able too..

Alas, I will not give a build for [Twisted Fate] and [Zilean] because I am not a big player of those characters, tho I keep them in the build for their passives as you will see

This guide is for those who know how to play [karthus], but want to add alittle zing to their premade... this guide is NOT recommended for beginner [Karthus] players

[Twisted Fate]... The luck... why? Because he gives u +2 gold every kill... great to farm up [Karthus] items quickly..

How to play? Read another Twisted Fate build.. I don't know lol

[Twisted Fate] Should be played AD carry for this team

[Zilean]... The Time.. why? Well because hes the cronic dude.. lmao.. no but really, his Passive is why you have him.. the Extra EXP will make [Karthus] hit level 6 before everyone hits level 4 (if you are playing him right)

[Zilean] should be played support for this team

This is you.. [KARTHUS].. or your team mate.. whoever, but you TAKE the life.. you ARE the life.. therefore, you define who lives and who dies (hopefully you and your team are more prone to the life part).. [Karthus] ult is just a mean machine.. it has a long cool down, but that's why as you see his masteries are 9/0/21 for Cooldown and well.. his runes are abit too.. not much damage early game, but still enough to hurt a level 3-4 with your ult (especially if your team is aggressive)

9/0/21
Offensive:

Why? Cooldown, ability power (abit) and magic pen (always needed)

Utility:
Why? Mana, buff to summoner spells, movement speed (as you are squishy), more gold, EXP and COOLDOWN (this is the bread and butter of the utility tree for karthus) extra gold per kill (or assist) and of course [Mastermind]

Straight forward, with the masteries and runes, your ult at level 3 will have a 70 second cooldown (and with items) that means every minute u can zap that pesky blue team (or purple).. rather then every nearly 2 minutes..

Here we go, Uptop is what I chose and I will explain why, but you have the option to replace it with what you feel (tho I feel this is great)

9x [Greater Mark of Insight]
Why? Magic Pen of course, great to get through that little bit of magic resistance those level 3-4 players have nyuk nyuk nyuk

6x [Greater Seal of Clarity]
[Karthus] is VERY mana dependent especially with his [Defile] on.. this helps (if you play him right) give you that ability to stay in lane farming kills with your [Lay Waste]

3x [Greater Seal of Vitality]
[Karthus] is squishy, he can get ganked easily.. and in team fights, he WILL be focused.. you know this.. if you don't.. play him and you'll see lmao... I find the extra health really helps, and instead of 9 [Greater Seal of Clarity] you have 6 and it doesn't effect your mana regen..

6x [Greater Glyph of Force]
Since you are in the utility tree, your damage early game will be laughable.. trust me it is, it's brutal, and altho your ult will deal just flat damage (250) which is great vs level 4 champions.. this will give you that leg up just a bit..

3x [Greater Glyph of Focus]
I find trading up 3 [Greater Glyph of Force] for extra cooldown is good.. you can always replace this with [Greater Glyph of Celerity] but I like the instant cooldown.. plus I find that his [Wall of Pain] pops up more even after using it..

NOTE: You can if you like use all 9x [Greater Glyph of Focus] or [Greater Glyph of Celerity] .. you can have a very quick ult ... but your damage will suffer .. your call

3x [Greater Quintessence of Swiftness]
1 word... survival.. Karthus is a turtle.. and this turtle needs some movement speed..

You should know this, i will not explain this a lot.. I will explain beginning items and situational items..

Dorans vs Boots + 3 health pots

Dorans = Your damage is increased, you have more health and mana regen (allowing for more spamming) .. downside you dont move as fast, and if u are getting hit by an enemy a lot, your going to have to teleport back and forth

Boots + 3 Health pots = A LOT less damage, but you can stay in lane more, move away more, and survive more.. use your discretion..

Either way.. get boots first, then 2 dorans rings.. or a doran ring.. boots.. second dorans rings.. after that fiendish codex for cooldown (as you will have your ult on cooldown by the time you get this) and then finally your sorcery boots.. OR the cooldown boots (depending on if they have a tanky team or not)

Now build right to Rabadons hat.. or morellos... Morello's is good if you are fighting a champion like [Akali] or [Mordekaiser] .. why? Because the active ability screws with their healing abilities making you get the kill and not die when engaging them.. just make sure to USE it lol...


Finally get rylai's for extra health.. voidstaff to melt them more and the hourglass cuz if they have a lot of CC you will need it (plus nothing more fun then popping your [Defile] in the middle of a team fight and then popping your hourglass as they focus you lmao..

You should know.. but 1 tip, stay in constant vigilance on the map, and with your team.. watch how fights go, you may not get the kill, but ulting at the right moment may save a teammate (making the enemy rethink if your team mate is gonna get killed) or helping him get the kill...

[Flash] and [teleport] why? because you can farm gold fast, you can teleport back and forth, or to a tower that's dying and it just makes getting to places easier...

Maybe [Exhaust] Instead of [Teleport] but I don't think its necessary..

I suggest tanky champs with CC such as [Skarner] [Volibear] [Jarvan IV] [Malphite] .. champions that can save life, luck and time.. lmao..

Try it out.. it's valid.. it can work if played properly... but as all team composition, champions, variables are concerned.. this may not always work.. your team might feed, you might feed, they may just be more skilled or have better team composition .. so try a few games.. but it makes them so scared to initiate and allows you to farm better and push.. give them that nice JOLT and hear "an enemy has been slain" or even better "YOU have slain an enemy"

Let me know what you guys think and how it worked out for you!

If you come up with a better idea on the same lines, let me know :)