So here's a great joke – League of Legends' Ezreal "is a lackluster AD carry." Pretty hysterical, right? At one point, this is something people genuinely thought. His Wave used to heal allies, for god's sake. He drove a very fine line between AD carry and AP skillshot mage. Then, with his highly-demanded and community-created Pulsefire skin, he shot up in popularity, and everyone found out, woah, this guy is good. And that's pretty much all he needed.
|Great on-hit Q shot||Doesn't duel amazingly|
|Global distance ult||Entirely skillshots|
|Built-in flash/AA combo||Small mana pool|
|Allied speed booster||Fragile early game|
Saying it was all his Pulsefire skin is misleading, of course – Corki and Graves were just as powerful during that time too, because right around the tailbone of Season 2 when everyone made the terrifying discovery of Malphite and his all-in-on-your-AD-carry kin. Escapes were needed, and simply boosted movement speed (Miss Fortune, Draven) and sluggish jumps with refresh powers (Trist) didn't do the job.
But it's more than that. During that time he had just about everything an AD carry could ask for. His Wave chipped great and shot through minions. His Q applied on-hit. He synchronized with Triforce brilliantly. He passively got more attack speed just based on use of abilities. He could debuff enemy attack speeds. He had a global range ult. His blink allowed him to instantly chase or run out of skillshots and ganks. He scaled incredibly well.
He's still one of the best AD carries I feel, but the much-needed Wave nerf, plus the Phage nerf, as well as the increased itemization for other AD carries has put him into just 'good, not hands-down best.' He still benefits well from his old kit, but the increased variety means he no longer wins any trade once he gets Berserker's and Phage. Trust me when I say that, if other AD carries could sync up with Triforce like Corki and Ez do, Season 2 would have seen them appear as well. Xypherous was not kidding when he said Phage was silly overpowered at the time.
And, most notably, he was originally supposed to be an intellectual psychic, glasses and all, before Riot felt it was just a tad too close to a popular anime at the time and instead turned him into Indiana Jones. Noxians...I hate those guys.
Probably First-time Ezreal (PFE)
There was, right as soon as the new Pulsefire Ezreal launched, a sudden influx of Ezreal players, and none of them knew what they were doing. Ezreal was already popular by that point, but the two things combined is what stuck him at the highest win ratio in the game despite (and not because of) the sheer gigantic volume of players picking him. Once his Wave got nerfed so it no longer dropped enemy attack speeds, he vanished from the highest win ratios, but he still floats around.
Pulsefire Effect is still in full swing, and he's still one of the most popular AD carries in lane right now, constantly 7k games more than anyone in the #2 slot. Part of it is that he's just fun to play. The long-range jab, free flash, and global range ult all are just satisfying to play, and he's got the delightful thrill of getting a few good kills and scaling fantastically into mid and late game. He's not just going to outright win, but he's strong as hell.
Core items on Ezreal almost feel silly to even mention – if you seriously don't build Triforce on him, you're missing out on the main reason to play Ezreal or Corki. Granted, of course, it's a midgame item and not a lategame one, but if you want a lategame champ, get Trist or Miss Fortune. Ezreal is all about hitting hard with strong midgame damage. If you can get a Triforce – or at least a Phage and Sheen by mid/lategame – you can wreck your lane.
From there, it branches depending on what you need. A Bloodthirster helps him poke and jab during drawn-out skirmishes and teamfights, Last Whisper helps him hit those tanks harder, Berserkers helps him pump out more auto-attacks, and a Guardian Angel is always critical for lategame carries. You can do without Triforce, but it's only recommended in certain instances, such as when your support is someone like Nunu. If you do, go standard – Infinity Edge, Phantom Dancer, Last Whisper. You lose the slow and the on-hit burst, depriving yourself of that sweet midgame, but your lategame damage is downright insane, and the Q hits like a truck.
Preparing Pulsefire Systems
Don't fall into the trap and try to make up for his earlygame tiny mana pool by buying mana or mana regen items (except for Sheen). Manamune charged into the Muramana might be interesting, but the toggle is bonus magic damage, not bonus physical damage. Meaning that the damage cannot benefit from crit chance, cannot grant you lifesteal, and do not apply to any of Ezreal's abilities other than Q.
Earlygame itemization for Triforce-oriented carries is a bit different. Most of the time, as ADC, you can get lifesteal items first (Doran's and Vamp Scepter) as well as attack speed to keep yourself sustained in lane. Or, alternatively, if you're pretty well farmed and ahead, go for damage outright and aim for just beating your opponent normally.
Ezreal is pretty good about that because he can go either way, or aim for the early Phage. Which, honestly, is one of the best items for him. It's not just the slow effect (that part is pretty amazing, even post-nerf), but the bonus HP and AD allows him to win trades, especially when complimented with some lifesteal. Sheen, meanwhile, is better served for after you get it, or Zeal if you prefer the movement and damage.
He has a bit of a problem if he falls behind, similar to say, Jax, because even though he scales well, he is pretty item reliant. Fortunately, he's a fantastic farmer, able to clear outlying waves with a well-aimed ult and zapping priority targets between auto attacks with his Q.
Ezreal's popularity makes it kind of silly to talk about how to play him other than that. Everyone knows most of the tricks, like zipping over walls, ulting during large fights, harassing with his Wave, and whatnot. He's tricky to play for newcomers, but with a little experience into the game, you can make Ezreal sing in your hands, and I recommend it. Nobody makes earlygame advantages into crushing victories quite as well as he does.