Hi, I'm James Diles. I'm currently a gold I player on EUW. I've played League of Legends ever since early season 1. I've played a ton of all the roles. I currently have 1800 wins in normal games. I haven't made many guides, but I hope you will like this guide :>
Introduction to Ezreal
Ezreal is one of the best ADC's in the game (at least imo). You have easy poke on lane with your Mystic Shot, and you have good escapes with Arcane Shift, not to mention securing kills with your Trueshot Barrage, or dealing a great initiative damage in the beginning of team fights!
If I'm playing Ezreal as ADC, I like to go for the usual 21/9/0 taking attack speed rather than CDR, and Armor instead of mana regen. It's all about how you use your mana, and your abilities. Sure, you can take the CDR isntead of Attack Speed if you want to, but I prefer it this way.
The general idea of an Ezreal Rune Page.
9x Attack Damage Marks
9x Armor Seals
8x Magic Resist Glyphs
1x Critical Chance Glyph
2x Life Steal Quintessences
1x AD Quintessence
Having 4% Life Steal from quints helps you sustain your lane, and taking 1 extra AD quint is enough for you to last his ranged creeps under your tower.
Flash: Flash is generally the best available summoner spell, and you can make a distance with Arcane Shift + Flash if you're in a tight spot
Barrier: I like to go Barrier, Always, since in SoloQ people usually try to counter you by picking Caitlyn, and I like to have barrier ready in case of a Caitlyn Ultimate. Not to forget Barrier is a great choice for playing ADC.
It is important to remember that Blue Ezreal is meant for dealing huge amounts of Poke with his 1 second cooldown Mystic Shot, while maximizing cooldown reduction as much as possible.
Blue Ezreal is NOT CAPABLE of dueling with auto-attacks, especially against the other ADC late game.
Also, if the enemy team isn't that tanky you might consider getting Blood Thirster instead of BotRK!
Just keep this in mind and keep up a good poke, and you'll do just fine :>