Hello guys! Its Misterfirstblood with a new ADC Champion Guide.
It's been a while since i released my last one because I took a break with League of Legends and Content Creation. But now I'm back and more hyped than ever to play some League and let you know about the Experiences i've made.

++ Super fast movement speed
+ Very good at kiting opponents
+ Mixed Damage
+ Midgame monster
+ One of the best dashes in the game
+ AoE damage

- Weak Early
- Not the strongest Late game
- Vulnerable to on Click hard CC
- Not good at melting tanks
- You can play around Zeri by standing behind minions (her auto attacks are skillshots)

P: Living Battery
Zeri Shields herself for 60% of the damage she deals to enemy Shields and gains 10% Move Speed for 3 seconds whenever she receives a Shield.

Q: Burst Fire

Range: 825
Cooldown: 1.52
Passive: Zeri's Attacks are treated as Abilities and can be charged up by moving and casting this ability. Uncharged Attacks deal (10-25^ + 3% AP) magic damage and consume some charge. A fully charged Attack deals (90-200^ +90% AP) + (3%-15%^) max Health and consumes all charge.
Additionally Zeri executes Targets below 60-150 Health.

Active: This Ability is treated as an Attack. Zeri fires a burst of 7 rounds that deals 8/11/14/17/20 (+110/115/120/125/130% AD) physical damage to the first enemy hit.

Passive damage applies Ability effects and cannot crit or apply on-hit effects

Active damage can crit, apply on-hit effects once per target, and hit anything that an Attack can. The Cooldown and cast time scale down with Attack Speed (max 1.5 attacks per second). 60% of excess Attack Speed is converted into Attack Damage.

W: Ultrashock Laser

Range: 1200 / 1500
Cooldown: 12/11/10/9/8
Cost: 50 / 60 / 70 / 80 / 90
Zeri fires an electric pulse that deals 10/45/80/115/150 (+1.5 of attack damage) (+70% of ability power) magic damage and Slows the first enemy hit by 30/35/40/45/50% for 1/1.25/1.5/1.75/2 seconds.

If the pulse hits terrain, it expands into a laser that applies the effects in an area and lands an critical hit.

E: Spark Surge

Range: 300
Cooldown: 22/ 20.5 / 19 / 17.5 / 16
Cost: 80
Zeri dashes a short distance and vaults over any terrain she touches, greatly extending the dash range. Her next 3 shots of Burst Fire pierce, dealing 80/85/90/95/100% damage to enemies after the first.

Hitting a champion with an Attack or Ability reduces this Ability's cooldown by 0.5 seconds but critical strikes will reduce it by 1.5 seconds instead

R: Lightning Crash

Range: 825
Cooldown: 100/ 85 / 70
Cost: 100
Zeri discharges a nova of electricity, dealing 150/250/350 (+ 80% bonus AD) (+ 80% AP) magic damage to nearby enemies and gaining 4 stacks (8 stacks when critical striking) of Overcharge for each champion hit for 6 seconds. Each stack grants 1% Move Speed. Hitting an enemy champion with an Attack or Ability adds a stack of Overcharge and refreshes its duration by 2 seconds.

While Overcharged Zeri also gains 30% Attack Speed, 10/15/20 (+ 15% AP) magic damage On-Hit, and Burst Fire becomes a faster triple shot that chains the bonus magic damage and 25% AD physical damage to nearby enemies.

Since Burst Fire is basically your auto attack and your role as an adc player is to use your auto attack all game you pretty much need to maximize this ability very first.
Mobility Spells are most likely the second spell you want to maximize and since it gives you not only wave clear but also a huge damage buff, you want to use it as often as possible and to decrease its rather long cooldown i recommend to max out Spark Surge second and Ultrashock Laser last.

Even tho Ultrashock Laser deals a ton of damage at level 1 the other options are just more important at lower levels in the game.

Immortal Shieldbow is one of the best survivability Items while Kraken Slayer ofers slightly more damage.
While its up to you on how you decide between these two items, the next best options to get your ultimate 3 Item Powerspike are Infinity Edge and Phantom Dancer in my opinion. Im not sure which of these is definetely the better buy at second but if you have these 3 you might deal a solid damage. Essence Reaver would be the next best generic item if you dont have to buy items for specific reasons.
After that your Laning phase might be over anyway and you have to think about what you might need in that specific game you are in.
The best Option for Damage is obviously Infinity Edge here, but if you are against a lot of tanks Lord Dominik's Regards is your best friend.

Runaan's Hurricane is a nice quality of life option that offers Waveclear and better Teamfighting if the enemies are grouped (you have a lot of attack range when your Ult and E buff is up).
The more defensive Options are life steal items like Bloodthirster and Blade of the Ruined King while Guardian Angel Titanic Hydra and Wit's End might be your tanky options that offer the most survivability.

If you totally need a QSS Mercurial Scimitar is okay too, but Wit's End will offer you a higher damage output while offering magic resistance too.

And if you need Heal Reduce Executioner's Calling is an option too, but not that recommended.

Lethal Tempo is by far the best Keystone rune on Zeri imo.
It not only offers you tons of attack speed, but it also increases your range after being fully stacked. Since your main damage source comes from auto attacking enemies with your Q ability, this is all you need to increase your damage by a ton.
Triumph is a great option to restore some health in longer fights and when chasing down the enemies, to further support your more risky playstyle.
Legend: Alacrity is a no brainer because as mentioned attack speed is pretty much your bread and butter stat you want to increase.
Last Stand can be replaced with Coup de Grace but i personally feel like you benefit from using last Stand a little more.

As i mentioned in my kog maw guide, you might need some tankyness in late game too, because you have to play Zeri a bit more agressive than other ADC's so thats why i recommend the Resolve tree as second option.

- Since your auto attacks are skillshots, good opponents might just stay behind minions and try to outplay you (it's the same as with Graves so keep that in mind and kill the minions before you try to engage or position yourself so that you can attack them for free
- Rift Scuttler will always be shielded so if you walk from bottom to mid lane or vice versa you can attack him and get a free shield + movement speed buff by doing so
- You can bind your Q ability with your mouse wheel and use it to auto attack if you feel confused when getting started with Zeri. It totally helped me out
- You can attack Baron's or Dragons' from outside the pit if you position correctly
- You can clear wards very fast by using Q and your Normal auto attack right after pressing Q
- When playing on blue side you can walk towards the rift and use your W ability through the wall to either push or poke your enemies
- When you are under a tower you can easily use your W to shoot through it and deal a lot of damage with an amazing range
- In teamfights it can be recommended to attack tanks instead of squishy targets to steal their shields and increase your own survivability

Because you will benefit from gaining shields its not nessesary but nice to have either a support on your side, that can give you shields, or an opponent with shields that you can steal using your passive, because you will gain movement speed by doing so.
Besides that its pretty recommend to play with either a very mobile support like Rakan because most of the enchanters and tanks might not be able to keep up your pace when you get tons of movement speed, or ones with lots of range that can buff you up and let you go ( Lulu is a good example, but Nami can do the job aswell)

Thank you for paying attention to my guide!
In my opinion Zeri is one of the most fun additions to the ADC Meta and by far my most played champion currently. I hope you enjoy her as well as I do.

If you found any mistakes please let me know, english is just my second language and i really tried my best here.