Enemies are considered isolated if they have no allies within a short range. Savor Your Fear's damage is drastically increased against these targets.
This includes neutral monsters, therefore it is advisable to kill the smallest first and then go against the toughest one, who will take considerable extra damage from Savor Their Fear Savor their Fear.
Invisible Menace Invisible Menace is activated when Kha'Zix Kha'Zix cannot be seen by the enemy team, therefore, it can be reactivated by going into brush or Void Attack Void Attack. This can be used as an effective form of harassment on the line.
Use the multiple periods of stealth guaranteed by Void Strike Void Strike to stunt enemies' abilities. Void Attack Void Attack gives Kha'Zix Kha'Zix incredible mobility.
If you've invested an evolution point in Void Strike Void Strike, you can use the brief 40% damage reduction to minimize the impact of a considerable amount of damage if cast correctly.
If you gank before level 6, try to keep Jump Jump available in case the enemy uses Flash Flash or other escape abilities.
From 6th level onwards, use Void Attack Void Attack as soon as you leave the brush to surprise the enemy. Use the second use (or the third in case you have evolved it) for your mobility in case you need to chase or flee. Evolving Taste your Fear Taste your Fear guarantees massive damage against isolated enemies and with little health; Useful for taking on the jungler or getting a quick kill from an isolated champion.
Evolving Void Spikes Void Spikes guarantees you great stalking and farming potential in early game. The slow serves both defensively and offensively. The blast radius of the spikes is tripled, if fired correctly, achieving maximum damage. (Enemies can only be damaged by an explosion, the same goes for the cure in Kha'Zix Kha'Zix).
Evolving Jump Jump guarantees you immense potential to gank, thanks to its great range (approximately twice Flash Flash) and its instant cooldown if you kill or assist the death of a champion. One useful tactic is to jump on an isolated champion, slow him down with Unseen Threat Unseen Threat, deal maximum damage with Savor His Fear Savor His Fear, and jump if he dies, ready to gank another lane.
Evolving Void Attack Void Attack grants you an extra use of Evolved Wings Evolved Wings before going on cooldown; giving you the possibility of an extra use of the passive, the extra movement speed and a third stealth. In addition, it gives a good damage reduction both physical and magical (except true damage), including the poison of Singed Singed or Teemo Teemo, for example, and other abilities of damage in area. However, syncing is very important, as the damage reduction is only effective during 1-second periods of stealth.