This build works by building towards Horizon Focus wich apply an extra 10% damage on slowing spells wich is why we need to build Rylai's second item after Liandry's wich will apply a slow wich will make your ult instantly deal 10% more damage on every champion after finishing Horizon also revealing them + the extra damage from first strike + extra mONEY, wich scales crazy on karthus, the only thing you lose in this build is Zhonyas, but i want damage, not some beta inmune gold statue meta, BIG DAMAGE BIGGER MONEY, also **** boots, sell that **** and buy more damage (Night Harverster might give a litle more damge but YOU HAVE NO MANA)

Just start with blue buff, farm rotations the hole game and at level 6 if you have gold buy damage and ult instantly, then everytime you have ult do the same again and again, no need for brains, just use r , and wait for the 5 of them to be alive, be careful of invades and zhonya's, try to ult on big fights for slows and assistances for the big money, sell boots and buy big damage item.

-Here`s some Pentakill lyriks so you get some motivation :)

Fellow armsmen, I ask you
Will you follow me tonight to break their spine
And reclaim what once was mine
Those cravens
Backstabbed me, deceived me
Never shall I tolerate their crimes again
Now let the hunt begin
7000 Souls, scared and daunted, such a tale of woe
Not too long ago, this village was a golden
Scene of hope
Call down the reckoning
To bring back hope and peace
Restore our gloria
To live forever
Bring down the dark regime
I know how to unleash the eternal power
Lead us to orderI am the lightbringer
(Yeah)
I am the lightbringer
Fellow warriors, I ask you
Should my campaign come to an end
There's way more to avenge
15 Million souls
Living in this realm without much hope
Not too long ago, this kingdom was a golden
State of hope
Call down the reckoning
To bring back hope and peace
Restore our gloriaTo live forever (yeah)
Bring down the dark regime
I know how to unleash the eternal power
Lead us to order
I am the lightbringer
Call down the reckoning
To bring back hope and peace
Restore our gloriaTo live forever (yeah)
Bring down the dark regime
I know how to unleash the eternal power
Lead us to order
I am the lightbringer