First off, this is my first guide/build I've put on here so there's probably gonna be mistakes. Just for a little context, my playstyle in league since season 2 has literally been to play every champion off-meta and to play strange builds that can sometimes be funny or broken (but often don't work the way I intend haha). However, this build is probably the most meta one I've made so far.

So you're still reading this guide. Not sure why, but I'll explain my reasons behind this build.

[*] First item is very situational. If you're mid with an easy lane then I like to go for an early Zeal and Berserker's Greaves before Eclipse. If you're up against a tank lane/team then an early Blade of the Ruined King is really good.

[*] Mythic item: Eclipse. Why Eclipse? Well to put it simply, it's synergises/stacks with your Dirty Fighting passive. Every auto attack fires off a second auto (unless you cancel for movement speed) and you gain a shield thanks to your passive. This in turn activates Eclipse's passive granting you an additional shield on top of your passive, as well as movement speed. The only downside with Eclipse is that it has a 16 second cooldown due to Akshan being a range champion.

[*] Phantom Dancer. The thought process behind Phantom dancer is that you gain movement speed on auto attacks and every four auto attacks (essentially two for Akshan)you gain a burst of 30% attack speed. A very good duelling and kiting item.

[*] Runaan's Hurricane. Simply put, Runaan's feels really good in team fight situations. You can sneak up on fights with your Going Rogue (W) and unleash a lot of damage. Your stacks to apply to every target hit by Runaan's.

[*] Infinity Edge. Because the damage is too good. You should have 40% critical strike from the previous two items to be able to effectively use IE.

[*] Blade of the Ruined King. On hit max health damage, attack speed and life steal. Not to mention that your third auto steals movement speed from your target. All round great item, can easily be earlier in your build path if you need it.
Another honourable/optional mention is Wit's End. This item gives a decent amount of on hit damage, magic resist, attack speed as well as on-hit movement speed.

If you got this far then you're either insane or trolling. Feel free to try this build out and let me know how bad it goes, this is my first guide so I'm always open to criticism.

Good luck.