If you are under level six, you can surprise enemies low on health by substituting Shadow Dance with Flash to net a kill.
Due to the low cooldowns of Akali's damaging abilities, the constant usage of Mark of the Assassin followed up by auto attacks can prevent her from running out of energy.
The stealth and slow of Twilight Shroud can be used offensively to provide cover and allow her to chain skill combos on the enemy more quickly, but can also be used defensively to prevent drawing enemy focus during team fights and to provide aid in retreating after team fights or running from ganks. Be wary of Oracle's Elixir, vision wards, as well as champion abilities that may reveal you.
Twilight Shroud is great for running from enemies in the jungle, especially near brush, as you can overlap them to break vision with both the brush and Twilight Shroud to juke enemies. You can drop a Sight Ward over a wall and use the vision provided toShadow Dance to a monster over the wall.
The ability can also be used to check brushes for enemies as the stealth prevents you from being seen by enemy champions in the same brush.
Be careful of the high energy cost at low ranks to avoid being caught without enough energy for Twilight Shroud.
Akali's strength greatly increases once she gains access to Shadow Dance. Before level six, you will oftentimes not be able to get close enough to enemies to proc her main damaging ability, Mark of the Assassin.
Once you hit your first 3 stacks of Shadow Dance, look around the map for an easy gank. Akali is an excellent roamer due to her burst damage and chasing power.
Akali can deal a massive amount of burst damage with Lich Bane combined with her passive by auto-attacking an enemy marked with Mark of the Assassin.
Since Akali is an assassin capable of dealing heavy burst damage to a single target, she is heavily countered by the target's magic resist. Therefore, purchasing a Void Staff and/or an Abyssal Scepter will ensure she can take out targets and keep her damage relevant throughout the game. Either item probably should be purchased after boots and Hextech Gunblade.
Rylai's Crystal Scepter is a great item to get because the slow is applied with her Mark of the Assassin and Shadow Dance, allowing her to stick to targets better and reducing the chance that they get away. The additional health also helps keep her alive longer during teamfights or small skirmishes.
Liandry's Torment may be an excellent choice especially when paired with Rylai's Crystal Scepter or Akali'sTwilight Shroud. The percent health damage is doubled for any target that is slowed. With her low cooldowns, Akali can maintain the debuff on an enemy constantly.
Purchasing Mejai's Soulstealer early can make you very powerful late game if you are able to earn a decent number of kills without dying. Although this is extremely beneficial, it is situational, relying on your early game performance and continued success.
Akali is most effective when making quick kills. The longer she has to stick around in a fight the more susceptible she is of taking a heavy amount of damage.
She isn't as effective against durable opponents because of her low base health and that she is a champion that has to burst a target down quickly.
After Akali's burst, she has to wait for her cooldowns in order to deal her burst damage again, which takes a while, even with cooldown runes and masteries. If fighting against her, use this time to take her down.
When you are chasing her, make sure you are aware of the amount of HP you have, due to the fact that she can nuke quite easily and score another kill on you.
Against an Akali, play more offensively until she reaches level 6; try to deny her early game, as she usually has the advantage once she gets her Shadow Dance.
Akali has very few offensive items early game. Zone her out so she can not farm, which will further delay her from getting her Shadow Dance. Once she does hit 6 try to bait her into using her ability on you if you can take it, as she is less effective the less charges she has.
Twilight Shroud will stealth her only if she remains in the AoE, Meaning that she will be out of stealth when she is out of the AoE or attacking. Try to move out of the AoE as fast as possible to prevent her from bursting you while in stealth, or pick up an Oracle's Elixir or a Vision Ward if she seems to be over using it.
Take great care when chasing Akali, as her Shadow Dance and her Twilight Shroud will make her a very effective juker and escape artist. Stun or silence her if she is being over-aggressive.
Champions with AoE abilities or reveals (such as Lee Sin) can be an extremely effective counter.