It's hard to say really, it depends how you build him, these builds however are mostly assassin/fighter and help you dominate the rift in style.

Zed has quite a few combos that most people don't see coming, it's important to remember that Mid lane against Zed is a 2v1, he's never alone, with his shadows you can constantly deal damage to your opponent without having to ever get in range of them.

First at level 1 start with Razor Shuriken and hit your opponent with as many as you can, if possible without throwing it through minions. Depending on the match-up put a point into Living Shadow or Shadow Slash, take W if it's someone ranged like Orianna and take E if it's someone like Yasuo who will be close pretty often. Then level the other so you have all three abilities at level 3 and then max them in this order.

Death Mark > Razor Shuriken > Shadow Slash > Living Shadow

After level three when you have all of your abilities, you have options. You're entire combo (if you're going to use everything) is use Living Shadow and try to put it on top of them, at the same time use Shadow Slash. Next, when they're slowed, throw a Razor Shuriken and try to land with both your own and your shadow's. Now, back up and let them come back to lane (they most likely started running away after you threw your Living Shadow) and if they step near your shadow, you should have enough time to use another Shadow Slash before it disappears.

The same as before, after landing your Living Shadow > Shadow Slash > Razor Shuriken immediately swap with your shadow and auto attack your opponent, especially if they are below half health you should do a lot of damage thanks to Contempt for the Weak and force them to flash away, especially if you can keep up with them and keep auto attacking.

For extremely safe poke you can obviously simply throw your Living Shadow and have it throw a Razor Shuriken but don't be afraid to get in range to use a Razor Shuriken yourself, especially if they're busy cs'ing.

After level 6 when you get your Death Mark your burst potential sky rockets, one strategy is to use the first combo, W > E > Q and immediately back up, let them get close to your Living Shadow and swap with it and immediately use your Death Mark it will almost always catch them by surprise the first time and usually end up with a free kill.

If you can, simply walking up to your opponent and using Death Mark can be pretty terrifying, no matter where they go you'll have Living Shadow to follow up with, however, be careful if you plan on saving your Living Shadow to stick to them, using Razor Shuriken before Living Shadow decreases your damage potential significantly.

Another option is to use your Living Shadow before you use Death Mark without swapping, as this will give you amazing juke potential if you can dodge skill shots by coordinating with your shadows. And, even allow you to land three Razor Shuriken quite easily.

If you have to you can use Living Shadow and immediately swap to get in range to Death Mark only do this if you know you can kill them easily, if their health is low enough or they don't have an escape.

I like to play Zed very aggressively and spam abilities in lane and abuse the fact that I don't use mana, so I mostly try and focus on getting a kill in lane and snowballing out of control, so I almost always take Ignite to be honest, I can't think of a more fitting Summoner Spell for Zed feel free to try Exhaust Heal or Teleport but I think most people will probably just stick to using Ignite

I know most of my builds don't have Blade of the Ruined King and most people I'm sure are just disgusted with that. However, I don't think it's really that viable on Zed anymore unless you build around it. As many people know Blade of the Ruined King was just nerfed and it's active and stats were all dropped significantly but it's on hit effect was buffed. Usually Zed doesn't aa much and simply kites with his shadows, so he doesn't have much use for the on hit effect. The main reason for Blade of the Ruined King was for the active and lifesteal as Zed didn't really benefit much from the attack speed and it didn't really have much AD either. So I prefer Ravenous Hydra as an alternative, it doesn't hurt your early game as much as buying those Daggers and saving for the 900 gold to upgrade them, but it doesn't help you stick to people as well as Blade of the Ruined King however, I think it's a worthy trade.

Offensive Item Options

Bloodthirster - Lots of AD and Lifesteal, can be helpful after you blow someone up in a team fight, can do one wraith camp really fast and be back to full health in time to W - E - Q someone

Maw of Malmortius - Survive enemy AP burst with ease, plus some damage

Mercurial Scimitar - For getting out of those annoying Veigar stuns

Youmuu's Ghostblade - Helps you assassinate a little easier, you don't need to use Living Shadow to get into Death Mark range and helps you stick to them, can also increase your damage a lot during your ult if you land a lucky crit.


Defensive Item Options

Guardian Angel - An amazing item gives good stats and its passive is great

Randuin's Omen - If there's only one AP champion on the enemy team, gives lots of health and armor, and active helps you stick to people or escape, amazing armor item

Frozen Heart - Lots of armor but no health, has some obviously wasted stats on Zed but the CDR is always welcome, mediocre item

Banshee's Veil - Helpful against teams with champions like Blitzcrank Thresh or Veigar and gives great stats

Spirit Visage - If you don't need the passive from Banshee's Veil and would prefer the CDR, especially helpful if you decided to go with Bloodthirster

I tried to keep this one short, but I tend to ramble sometimes, either way, if this build helped you I''d love to hear about it and if you have any comments or things you think could improve the build I'd love to hear it as well, just leave a comment and I'll respond as soon as I can. Most importantly though, remember to "Perfect one's technique, and kill all ninjas who refuse to embrace the shadows."