Ever wonder how Evelynn got her name? She proclaimed herself the widow-maker when she entered Piltover and assassinated Heimerdinger's wife.

Up until that day, Heimerdinger was in favor of a peaceful resolution between Demacia and Ionia. It was beautiful sunny Tuesday afternoon, and the brilliant scientist was doing extensive research in his secret lab. Eve had been misinformed on her targets location. The target was expected to be at home, alone, working on one of his gadgets. After picking the lock, Evelynn entered quietly and found his wife preparing dinner. She should of known better then to take the kill contract on such short notice and with such an early deadline. She would make a corpse tonight, kill contract or no! Silently, she crept behind Heimerdinger's wife and ravaged her as no other woman can. No one saw her and this story is unverified. However Evelynn did pass this story on to Shaco, who flashed his wicked smile and also refuses to confirm or deny Eve's involvement in the assassination.

There are plenty of AP Evelynn guides out there. Most of them have many of the same items. What separates mine from their's is that I realize how necessary sheen is, and how hard it is to get it by early/mid game. I then balance it with the fact that she still needs to be able to nuke hard and get out quickly.

Pros
Good burst
High mobility
Invisibility
Strong debuff
Extra gold income (from runes/philosopher's stone)

Cons
Squishy
Small mana pool
Requires map awareness
Always focused in team fights

Greater Mark of Magic Penetration + Greater Glyph of Scaling Ability Power - For increased damage output throughout the entire game

Greater Seal of Gold + Greater Quintessence of Gold - Evelynn has no ranged harass which can lead to having to tower sit early game. She also needs sheen by mid game. These runes will help her get there.

21/0/9

Evelynn needs added magic penetration and ability power and Executioner to power her ganks. When enemies get away with little/no hp Evelynn doesn't get needed stacks or hp back from the passive of Agony's Embrace.

I also get Good Hands - this can help a lot when your team just barely loses a team fight and they don't teleport back b/c they want a tower or dragon.

Swiftness helps to get in and out quickly (before getting cc'd)

I don't get Runic Affinity since AP Evelynn doesn't really have time to make good use of buffs in a team fight.

Instead I opt for one point in Greed

Regrowth Pendant/ philosopher's stone - needed for staying in lane early game. With no ranged harass and a small mana pool, the gold / 5 seconds really helps you complete you items even when you can't farm.

Sorcerer's Shoes - increased burst
or
Mobility Boots - quicker ganks (don't have to be as map aware)
or
Boots of Swiftness - get in and out quicker

Sheen - increased burst (get this before you finish your boots)

Mejai's Soulstealer - By now you should have a high enough rank of ravage + it still being early/mid game that kills will be the easiest that they will ever be (unless you get super fed for late game).

Lich Bane - Natural follow-up for Mejai's + Sheen (increased burst)

Morello's Evil Tome - As team fights occur more frequently, you'll find yourself needing more mana and wanting to go invisible (or cast ravage) sooner. The AP is also great for more burst.

Rabadon's Deathcap - If they aren't stacking magic resist get this to start one-shotting soft heroes. (otherwise replace with void staff)

Rylai's Crystal Scepter - Sell philosopher stone and get this to max your killing / escape potential.

Level 1 - Hate Spike - for early game farm potential (hit this right as your auto attack lands, or sometimes instead of auto attack)

Level 2 + 4 Shadow Walk - 10 seconds is never enough to get proper positioning (just trust me)

Otherwise max
1) Agony's Embrace (heal and move speed to get in and out of position),
2) Ravage (burst damage + debuff)
3) Hate Spike (sustained damage + proc for Sheen and Lich Bane)
4) Shadow Walk (This will let you follow the squishy around till he gets away from his team)

Flash - An absolute must. Unexpected pink wards and oracles can put Evelynn in a tight spot. Some fights you may have to flash in to get rid of that dam oracle carrier. Don't be afraid to flash under a turret to pick up a free instant kill.

Ignite - Optional. I run it so that I can kill those pesky healer types with ease.

Exhaust, Ghost, Surge, and even Smite are legitimate replacements. If you steal baron and then die it is almost always worth it (just fyi)

Evelynn can lane anywhere with regrowth pendant.

solo: Eve's ravage will be very useful in ganks, even before you get sheen.
partner: Eve will not risk losing her tower while she farms under it.

I don't play at all aggressively until I get sheen, with the exception of a few situations.

1) My laning partner has harassed them pretty low
2) They have to little mana to deal much damage
3) Someone is coming to gank my lane
4) Another lane needs help, and my lane is not at risk of of receiving a lot of tower damage

I don't always get much farm, depending how well they can harass me. The gold gotten from runes + Philosopher's Stone take care whatever farm I'm lacking.

Once you have philosopher's Stone + Boots + Sheen, you need to keep an eye on gank opportunities.

1) Aggressive players who have to dive in to harass (like Xin Xhao, Mordekaiser, and Nasus). Get your teammate to harass and lure some then come in for the kill.
2) Over extended lanes.
3) If high on mana, create a gank opportunity by Shadow Walk + Ravage + one or more Sheen procs/Hate Spikes.

Always make sure to be ready for the counter gank by the enemy jungler (especially Lee Sin, who can find you while your in Shadow Walk).

Usually your role in a fights is to kill or almost kill a squishy and get out alive, then sometimes you can go invisible and come back in to clean up.

Things to keep track of
1) Exactly how much burst damage you do

2) Scout: Before a fight starts look in the nearest bushes for the rest of the enemy team.

3) Don't Scout: Its not always a good idea to scout if they have been getting oracles and pink wards a lot. Take note of which players buy oracles, keep track of how they play.

4) Taking care of oracles

a) Tank Baiter - Do they try and bait? You can flash or come from behind, with your team right behind you, and nuke him before their team can save him, or alternatively, try to lure him in and use malice and spite to escape as your team closes in on him.

b) Tank that is surrounded by team - let the fight start with you nearby and safe, ignore him once he initiates and go ravage the softest carry/healer (or whoever your team focuses).

c) Non-tank - ask you team to focus the squishy, use bushes and corners to help you close distance when you try to kill him.

Remember once you have stacks, they will be waiting for you to come in. Make sure to let your team break that focus, or to out-maneuver and position yourself so that they die anyway.

Evelynn, built like this can die instantly... but

Realize that as you do well it takes some pressure off the team as a whole.
1) The other team buys Oracle's Elixir and Vision Ward (literally wasting money, if you can outplay them)
2) The more fed you are, the more difficult it is for them to jungle and push lanes and ward alone (since you could easily kill a Teemo or Master Yi at nearly full hp before he can blind you or flash away)

If you are (0/2/0) and you lost your lanes tower...or worse. There is still hope.

Realize that your team will hate you (first b/c you picked Evelynn, second, because they think your feeding, thirdly b/c you picked up Mejai's).

Evelynn's early game is hard. You will learn to last hit safely (and sometimes not at all) with practice.

Don't initiate ganks. They will crush you so fast.

Let a 1v1 break out and "save" the day (preferably not letting your teammate die, remember to keep in mind how much damage you can do to help, the enemy doesn't need a double kill).

Use Ravage right before the your teammate is about to cast/recast his main damage dealer.

Timing and position is EVERYTHING.

Sometimes you open with a ravage on the tank, net the team a kill, and get get everyone away or win the team fight. Other times you ravage, and kill Veigar, only to have his Dark Matter obliterate you while stunned. A good idea of how fast their reflexes are and how accurate they cast can help you decide who to burst and when.

Tips
1) When you enter team fight look to see if enemy cc's are far away or that you will kill the target instantly.

2) You can enter the fight, when they lack the damage output to finish you before you get healed enough from an enemy kill, to survive.

3) If a teammate takes a stun, often times u can slip ravage on the stunner and get safely away before the stun is ready again.

General rules:
1) A good Evelynn makes use of invisibility, move speed, high burst damage, and great positioning, to quickly decimate unwary enemy champions.

2) Evelynn picks her fights, if she dies to save a teammate, it is intentional, if she lets teammate die, it is also intentional.

Me and Evelynn go way back. I knew her before she killed Heimerdinger's wife. We were friends before she dated Twisted Fate. In fact, me and Evelynn had many emotional conversations, before she finally decided to pursue him. May lady luck smile on them both... but back to the point.

Season 1, I played over 100 ranked games with her, of which I won 57.5 %. Season 2 I stopped playing her b/c I felt that she had been nerfed to much. I've been reminiscing the days when I would carry my team and instant kill Veigar before he could stun me. Recently, I watched a video of this ranked AD Evelynn who would get 3 or 4 GP/5 items and go mid, and do well.

So I toyed around with different builds and runes and masteries and concluded that this fits my play style and works.

I won 8 of my last ten games with her (normal). Here's a screenshot.
If you wanna queue with me and see how I play her, feel free to add "x DreadMist x".

P.S.

Evelynn wants to formally invite all voters for this guide to her wedding reception, to be held on New Years Day, at 3:00pm sharp, at Hiemerdinger's house (believe me, you don't wanna miss seeing all the cool gadgets). Rumor has it that Twisted Fate and Evelynn want to consummate the marriage by finishing off that haughty inventor once and for all.

No hard feelings Heimerdinger?

Good Luck out there!