Pros + Very strong mid game if ahead + High mobility/ Escape potential + Easy and fun wave clear/ laning phase + High outplay potential + High damage

It's a fun champion to play and master, I personally never get bored of playing this champion and once you can play this champion to it's full extent, it will pay off.

Cons + Medium to learn but hard to master + Very high skillcap + Weak against CC + Hard to play in teamfights

He is very good if you master him, though his combos can be very unique and situational. It will take some time to learn but again, it will pay off

Contempt for the weak (Passive): Zed's basic attacks against targets below 50% Health deal 6-10% of the target's maximum Health as bonus Magic Damage. This effect can only occur once every 10 seconds on the same target.

Razor Shuriken (Q): Zed and his shadows throw their shurikens, each dealing 80/115/150/185/220 (+90% bonus Attack Damage) physical damage to the first enemy they pass through, and 48/69/90/110/132 (+54% bonus Attack Damage) physical damage to each additional enemy.

Living Shadow (W): Zed's shadow dashes forward, remaining in place for 5 seconds. Reactivating Living Shadow will cause Zed to switch positions with this shadow.
Passive: Zed gains energy whenever he and his shadows strike an enemy with the same ability. Energy can only be gained once per cast ability.

Passive: Zed gains 30/35/40/45/50 energy whenever he and his shadows strike an enemy with the same ability. Energy can only be gained once per cast ability.

Shadow Slash (E): Zed and his shadows slash, dealing damage to nearby enemies. Each enemy champion hit by Zed's slash reduces Living Shadow's cooldown by 2 seconds. Enemies hit by a Shadow's slash are slowed by 20/25/30/35/40% for 1.5 seconds.

Death Mark (R): Zed becomes untargetable and dashes to an enemy champion, marking them. After 3 seconds the mark triggers, repeating a portion of all the damage Zed dealt to the target while they were marked.
Zed becomes untargetable and dashes to an enemy champion, marking them. After 3 seconds, the mark triggers, dealing physical damage equal to 100% Attack Damage + 25/40/55% of all damage dealt to the target by Zed while the mark was active.The dash leaves a shadow behind for 6 seconds. Reactivating Death Mark causes Zed to switch positions with this shadow.
Reaper of Shadows: Zed reaps the shadow of the strongest foe slain under Death Mark, gaining 0 attack damage. ([object Object] + 5/10/15% of the victim's attack damage.)

Since in season 10 a lot of stuff has changed and been different for Zed. If you skip to rune page 5, you'll see my go-to rune page. I'd go duskblade over ghost blade if you have a lot of kill pressure. If you don't, go ghost blade. I'd also say go cooldown reduction boots every game with the conqueror rune page. The rest of the items are up to your preference. The new death's dance is also good against ap/ad and gives you a lot of armor, it's basically a maw replacement but better. Obviously go armor lord dominiks every game imo, that's a must for me. Also, get edge of night if the enemy have a lot of spells as in morgana, lux, elise, etc. Read the info boxes below for more information. Late game you could always sell your boots for black cleaver or an item which you like. Umbral Glaive is also quite a good item, though I always sell it late game (if it really lasts that long)

The rune matchup difference explained, the following runes I personally sometimes switch around depending on the matchup.
Let's start with Nullifying Orb and Scorch. If you're going against an AP midlane or in general a heavy AP team I'd recommend going Nullifying Orb and Transcendence, always go Transcendence whether you're going Nullifying Orb or Scorch. Scorch basically when you're not against a very heavy AP team, and want to lane dominate.
It again is an all round rune page, therefore my go to page.

Ravenous Hunter and Ultimate Hunter is a simple one. I'd recommend Ultimate Hunter since you'd have way more impact late game if the game would get to that state. Ravenous hunter is good, yet I personally would rather go for the damage and pressure.
As you know, Zed is known for his damage and impact on the game whether it’s snowballing or lane clearing and roaming.
For Taste of Blood and Sudden Impact the players difference is key, Taste of Blood gives you more sustain and also a little ad, where Sudden Impact gives you lethality every time you cast w, which then does more damage. So it's kind of just player based and what kind of lane you're against.
Eyeball Collection and Ghost Poro is quite self-explanatory, read what they do and you'll find out, though, going Ghost Poro is the ''safer'' version.

When it comes to the Precision rune, it's fairly easy. You always go Coup de Grace with mostly Triumph, Legend: Tenacity or Legend: Alacrity. Regarding the new update you also could go with Presence of Mind. It’s an all round well build and page rune if you basically just feel like playing Zed, though I prefer going Sorcery. What's fun to play around with also is Presence of Mind, give it a try and it might work out for you sometimes. It surely works out.

For the Resolve one I wouldn't change alot apart from tweaking it to your own prefrence. It’s basically just burst protection and especially well against burst midlaners. Combine it with black cleaver as second item as when they buy Ninja Tabi they cannot stop you. This rune page coming with the building page I made I like to refer to as a CD asap rune page/build

Now you might not agree, and that's fine. But I personally do not like to build the new Sanguine Blade. The thing with Sanguine Blade is that I think it's not really made for Zed but rather for Jax, Kled or anyone that has attack speed. My personal build which I will show in the build option aswell is Youmuu's Ghostblade- Duskblade of Draktharr-Boots- Lord Dominik's Regards- Guardian Angel/ Phantom Dancer or whatever you like and then build Sanguine Blade. Tho I think I'd honestly rather go with the new Stormrazor, it's a solid item and imo WAY better than Sanguine Blade. I will also include a build coming with that above in the build section.

Let's start with Duskblade of Draktharr, it's a pretty good item as zed. Especially in the lower elo where roaming is game deciding having a Duskblade of Draktharr is very nice. Though I personally don't really like the item that much, I much prefer other items such as Lord Dominik's Regards and so on. Not saying it's bad, just saying it's not my favourite, though most of the time, I do buy it for the early game pressure.

Going on to Black Cleaver is also a bit weird. It's a good item for zed but I don't always build it, against squishy teams building black cleaver wouldn't be the best idea. Going for a Phantom Dancer or a different ad item which could help you would pay off more. Building it against tanks and or a tankyish team is then a good idea.

Edge of Night is not that good anymore for Zed, it gives you hp, damage and lethality. But the new nerfs to it in the preseason/9.23 makes it basically hot garbage. It's passive has saved and won me fights several times though. So if you're playing Zed, try to get Edge of Night if you want to teamfight and be all around safe. Though, there are better damage options with for example the new Stormrazor. Against people like ahri morgana and elise etc, get it.

Youmuu's Ghostblade is also a must have on zed, me and many others prefer to have it as first item, since it's passive is very good for laning phase and roaming.

Phantom Dancer is just a fun item to have most of the time. It gives crit, it's passive can help you out (shield) and the attack speed/movement speed is also a nice thing to have. Many people find this to be a stupid build and would go much rather for another item, which I actually agree with. Phantom Dancer is quite a situational item. Meaning that if you're against a team with a Sejuani and a Sion, I wouldn't go Phantom Dancer either. Build it against squishy teams. You can also go for Statikk Shiv, but that's personal prefrence.

With boots it's pretty self explainatory. Ninja Tabi against ad teams/heavy ad teams and Mercury's Treads against teams with magic damage and lots of cc stuff, it's annoying.

Lord Dominik's Regards is a VERY good item for zed, the damage and flat armor pen is amazing especially in the early to mid game. Therefore build example 4 is one of my favourites to do. And? It's cheap.

Hexdrinker is quite situational since I personally actually never buy it apart from in ranked sometimes. It's good for situations when you're against for example a Malzahar. He can deal lots of damage in laning phase and his ult is the worst part, which you can buy Mercurial Scimitar for.

The new Stormrazor and Sanguine Blade. Stormrazor? It's pretty good actually. I highly recommend you try it and I might get it some if not most games as it gives you good damage and 25% crit, if you combine the build with Phantom Dancer it will give you 50% crit, which I very much like. Sadly though, I don't actually like the new Sanguine Blade, It's not that bad for zed but the other items are just way better. It's okay when 1v1ing and splitting but is that really what you should do with zed all the time? I personally will not build it, give it a try and see for yourself how you like it and play around with the items, be creative. That comes with every build and rune I gave up there in the section for builds and runes. Remember that about this guide, though obviously it's a guide. Goodluck!