First of all, this is the first build i posted (i play the game for 3 weeks at the time i posted this)
This build is something i am using with mordekaiser atm.
Its slightly slow to build up but, if you farm well and get some kills here and there i can assure you: enemies will run from you. For me this build is also good for doing a gank on an enemy.

As most of the players know already, mordekaiser is a great farming character and it is no difference with this build.

Boots to lich bane:
Once you got your sheen, it kinda depends on how much money you are gaining, if you get a lot income then you might want to skip straight to the lich bane and get the boots afterwards.

Force of nature:
Depending on what you are up against you might want to considder getting a thornmail instead.

Rabadon cap:
I usually have 2 rabadon caps in very late game tho if you want some more magic penetration you might want to get the void staff(2 rabadons will give you around 570 ability power, void staff makes it look less in the guide!!!). Or if you want to completely solo, sell will of ancients and get a third rabadon.

The will of ancients will give nearby allies an offensive buff which can come in handy in teamfights.

This build isn't really unique or anything but if you get your build up, then pretty much anything that gets close to you is dead. If they run off with low health and u cant hit them, use your flash and you will still get them :)

Pro's:
-easy farming as usual with mordekaiser
-Deal massive amount of damage
-midgame will end up in people running away scared from you
-late game = OP

Con's:
-Slightly slow to build up
-Low HP (make sure u have a shield up when going for an enemy and make sure you kill them first :D )
-If you dont farm well, you are going to have a hard time.