I will not wirte ages 4 this build. Just some short tipps.

Runes are easy: Live and a bit magic pentration to get more dmg with burning agonie.

Are easy, too. You just have to make a bit magic dmg and have many live. You will kill the most even 1vs1.

I've choosen boots of swiftness to get some kills. Mundo needs a longe time to kill his enemy, so you need it. The rest is just 4 live. With spirit visage you ult will heal 94% of your max. live. The last Item, thormail, is just vs damge dealer. If you have to play vs magicans choose force of nature.

Its the same like boots of swiftness: Just to get some kills.
Choose other, if you think you get enougth, but never heal! It will give you just a little part from your live.

Pros:
-You can survive easyly and help you mates with infected cleaver this way
-With that many live you dont have to go b at start and u'll get much exp
-You can follow your opponents even behind their tower without problems and kill them.
-you can use infected cleaver to get kills easyly, if they run away.

Cons:
-Its not that easy to get the kills all time because you have not much dmg
-Its nerly impossible to get that overfeed so u can buy the whole eqipment.

I said it before: Help you mates with infected cleaver! its that easy and u wont die that easy for example ashe or lux will.
The best way it to run into many enemies nealy the grass. In it some dmg-dealers have to hide. I think you know the rest ;). BUT: Its very important the enemys attack you BEFORE youre mates try to kill them. Yust activate you skills than ;)

Thanks 4 watching. Pls Vote and comment :)