Pros

High sustains with her built-in spell vamps
High base damage due to her passive
Very mobile with her ultimate
Closes gaps and bursts targets effectively (No Escape)

Cons:

Countered by pink wards / oracles and easily focused down
Has many counters top lane
Very reliant on farm as snowballing is important to her assassins play style. Farm to level 6 ASAP.

Pre-Laning Phase

If your team chooses to force a fight at level 1, or you are invaded by the enemy at level 1, you will still get Mark of the Assassin (Q) as your 1st skill. Focus whichever enemy is in range. Do not go out of your way to attack enemies that are farther away. At level 1 you are very squishy and do not have Twilight Shroud (W) to protect you. You must Ignite the target you choose to focus right off the bat. This will grant you a bonus 10 AP from your masteries giving you even more damage at level 1. If you are caught off guard you should be able to flash away and not be chased down because you have early boots of speed.

Laning Phase (Levels 1-5)

You will always want to take a solo lane. Choose to take top solo or mid solo depending on which opponents you will be facing in the mentioned lanes. You want to face opponents who have low, non-burst damage early on such as Nidalee, Singed, and Wukong. Switch lanes with your teammates to avoid difficult matchups such as Urgot, Brand and Renekton. Being able to dominate your lane is the only way that Akali can safely and effectively snowball a game into your team’s favor and ultimately into a win for your team. Start with Boots of Speed and 3 health potions. You are going to put your 1st skill point into Mark of the Assassin (Q). Once the creep waves have arrived to the halfway point of the lane, begin to last hit. Attack creeps only when they are 1 auto-attack from death. Your auto-attacks deal huge damage early on because of your passive and runes, so last hitting effectively should be a breeze. To harass, you will spam Mark of the Assassin (Q) on your enemy whenever you are in range to do so. Doing this will not aggro creeps so you can keep doing it for as long as you can. Last hitting is still your number one priority until level 6, so you should prioritize last hitting over harassing. To take the Mark of the Assassin (Q) harass to the next level, utilize your Twilight Shroud (W) as well. Land Mark of the Assassin (Q) and then use Twilight Shroud (W) in between you and the enemy. This should effectively zone your enemy from gaining experience and successfully last hitting. If they choose to stand in the shroud simply auto-attack them to proc your Mark of the Assassin (Q) for some massive damage. This zoning/harass technique can be reversed by using Twilight Shroud (W) first and then getting in range to land a Mark of the Assassin (Q) without any follow ups.

Laning Phase (Level 6+)

At this point you should have recalled to base at level 6 and with 1300 gold from last hitting (roughly 55 minions slain). Buy a Hextech Revolver, a health potion and a sight ward. On the way to your lane, you should have gained 3 stacks of your ultimate. Place your ward on the side where the jungler is most likely to gank from and begin extreme aggression. You are going to use the same harass/zoning tactics used before level 6 only this time you will proc Mark of the Assassin (Q) hopefully 3 times and score a kill. Get in range of your enemy and land a Mark of the Assassin (Q). Wait until it is floating above your enemy, and then count to 2 seconds. You are about to use what is commonly known as a “Double Proc”. After 2 seconds of having Mark of the Assassin (Q) hovering on top of the enemy you are going to Shadow Dance (R) on them, attack to trigger the mark, then quickly use Mark of the Assassin (Q) again and attack them again. Keep up this harassing, and when you feel confident enough to go for the kill, do so. Remember that when going for a kill always use your ignite first because it will give you 5 bonus AP before you use any spells, giving you a slight damage boost.

Farming

Farming is very easy on Akali. If there is a creep with half hp you may choose to use Mark of the Assassin (Q) then proc it to heal yourself and kill the minion. Be careful of how many times you do this because it pushes your lane and makes you vulnerable to ganks. Once you have Crescent Slash (E) at rank 3 you can use this ability twice on the ranged minions and kill them. Crescent Slash (E) uses a lot of energy without any refunds. Spamming this may make you vulnerable to ganks because you have no energy to use Twilight Shroud (W). To alleviate the energy cost slightly use Mark of the Assassin (Q) on one of the 3 ranged minions, then use Crescent Slash (E) and finally auto attack the creep that was marked with Mark of the Assassin (Q). Rinse and repeat. This method should heal you because of your spell vamp, allow you to farm effectively and is energy manageable. Again, do this only if you are confident you can avoid being ganked because this does push your lane quite hard.

Strength: Dueling

Once you are level 6, you should be able to kill anyone on the map if you have a Hextech Gunblade and 3 charges of your ultimate. In your lane you are going to perform the harass discussed earlier and attempt to score a kill. Do not be afraid to exchange blows because you will heal yourself back to full health in 1 creep wave due to your spell vamp. Your damage will often take people by surprise, so much that when you are ganked later in the game most of the time you are able to win 2v1 ganks against you especially when using Twilight Shroud (W). You will be able to 2v1 because this ability allows you to avoid damage, position yourself and wait for your cooldowns and energy to refresh. Remember to use your Hextech Gunblade for the extra damage and to prevent the enemy from escaping.

Positioning

As Akali you should always be the last person to enter a team fight, even more so if the enemy has stealth detection such as Oracle's Elixir, a pink ward or a revealing spell. Stay in the back of your team until the suppresses/stuns/silences and other crowd control effects have been used. Then with your Shadow Dance (R), dive right for the AD carry. Remember to stick to 1 target until they are dead, otherwise your ultimate charges will not refresh and you will be found in the middle of the enemy team without any way to kill them. Once you dive for the carry and remove them from the fight take some time to look around you. Is the enemy taking their time to protect who you are focusing? Are they going to focus you? If they are, use Twilight Shroud (W) and wait inside it patiently until they are forced to focus somebody else. If they are not, continue killing your target and progressively move on to the other squishy targets or those who are about to die. Do not be afraid to take all the kills for yourself. That is simply how Akali is played.

Akali Ability Rotations

Combo 1: Hit the enemy with your first Mark of the Assassin then wait for the cooldown to be gone until you Shadow Dance towards them and proceed the combo.

Combo 2: In Team Fights use Mark of Assassin, then immediately Twilight Shroud first and wait until they focus someone else, then proceed to attack by Shadow Dance and then another Mark of the Assassin.

Beyond rank 1, the Mark of the Assassin debuff lasts longer than the cooldown, allowing Akali to cast Mark of the Assassin followed by Shadow Dance, then finishing with another Mark of the Assassin for extremely high bursts of damage.

More specifically, Mark of the Assassin --> wait for the cooldown --> Shadow Dance --> autoattack --> Mark of the Assassin --> autoattack. If you are under level six, you can surprise enemies low on health by substituing Flash for Shadow Dance to net a kill.

General Playstyle

Akali relies on her aggressiveness to overpower and kill her enemies. She needs to dominate her enemies in order for her to be successful. You must tailor your playstyle around this mentality by taking advantage of your stealth, dashes, wards and sheer killing power which may allow you to fight outnumbered and come out ahead. A weakness of Akali is that she has to be fully committed to her targets. Your enemies may exploit this and use it against you. With practice you will learn how to focus different targets and when, or when to switch targets and how to do so. As Akali you must also not fear to soak up damage as you will heal a lot of it because of your item build and runes. This may be true but you should be very wary of non-targetable damage-dealers such as Mordekaiser and Kennen which can harm you severely. As Akali you must also be extremely careful of going into battles versus enemies with high damage and stealth detection.

Team Fights

Your goal is to kill the enemy carry first. You must never initiate a battle as Akali unless they are very split up. As a general rule, however, you should always be the last person to go into the battle. When a fight breaks out, wait for the major damaging or disabling abilities to be used, then dive straight for the carry. If focused, use your Twilight Shroud (W) to avoid focus. After removing the carry from the fight by either killing them or forcing them to flee, switch to the targets with lowest health.

Countering Akali

When Akali uses Twilight Shroud,she is very vulnerable because she will use Twilight Shroud to hide and wait for her abilities to come off cooldown. Having a Oracle's Elixir or Vision Ward will make her vulnerable and easier to take down. If your playing against an akali (Where she is on the other team), the just make sure you carry a pink ward for team fights so she cant wait for her CD's while in shroud.

One of the most important aspects of Akali is mastering the use of Twilight Shroud (W). The stealth will last for 8 seconds and immediately stops all creep aggression. During lane, when the enemy decides to harass you with auto-attacks, you should use Twilight Shroud (W) as soon as he hits you. This will leave him slowed, with no target to attack (because you are now invisible) and he will be taking damage from your creeps because he attacked you. This is indirect harassment that can be followed up with your Mark of the Assassin (Q) for increased damage. It is things like these that give you the edge in the laning phase.

One of the strongest harasses with Akali is using Shadow Dance (R), then Mark of the Assassin (Q) , Twilight Shroud (W) and then 1 auto-attack to trigger the second component of Mark of the Assassin (Q) . This will be very strong burst damage that becomes increasingly intimidating the faster it can be pulled off. You can add some increased damage by using Crescent Slash (E) as well, but be sure to have your energy bar full before attempting this because it will use up most of it and you do not want to be caught off guard without any energy to use your spells.