Rankbreaker – This is a great item for The Joker as it gives him damage, movement speed and armor pierce so he can do the most damage possible and start to roam to the mid lane and enemy jungle. It also gives some cooldown reduction so you can poke the enemies with your first skill.
Hermes’ Select – These boots gives you two times the movement speed above all the other boots while out of combat. These boots helps you roam a lot and pick up some kills for you. The boots also works really well with rankbreaker as it gives the Joker the ability to roam all over the map.
Omni Arms – This item is immensely helpful for your combo. The extra damage really helps you burst any squishy and even some warriors. It also gives you a bunch of different stats that help you in every way.
Fenrir’s Tooth – This item gives the most attack damage of any item. It’s passive increases all damage done to enemies who are below 50% HP. This helps you finish of any enemies that survive. This combined with your first or third skill can finish of any enemy.
Muramasa – Since armor is the main problem for The Joker as it prevents his burst. Muramasa combined with rankbreakers armor pierce help you deal maximum damage to warriors and even deal significant damage to tanks. It also give even more cool down reduction so you can do your combo more often.
Death Sickle – Is your enemies doing so much damage and you are not able to kill them faster than they kill you? Then you really need to build this item because of its passive. It makes you win the 1v1 fights or survive lethal hits in team fight.