Burst damage and backline assassination.
Burst damage and target access
Hitting a champion with 3 separate attacks or abilities in 2s deals bonus adaptive damage.
Gain a burst of Lethality and Magic Penetration after using a dash, leap, blink, teleport, or on leaving stealth.
Collect eyeballs for champion and ward takedowns. Gain permanent AD or AP, Adaptive for each eyeball plus bonus upon collection completion.
Unique champion takedowns grant permanent out of combat MS.
+18 Ability Power or +11 Attack Damage, Adaptive
Takedowns restore health and grant bonus gold.
Deal 7% more damage to low health champions. Gain AD/AP after kills or assists.
Fizz is able to quickly and reliably proc Electrocute for the burst damage needed to secure any kill.
Between Fizz's [Q] and [E] Fizz can easily proc Sudden Impact for bonus Magic Penetration when jumping onto his target.
Fizz is an assassin and is all about kills and snowballing and Eyeball Collection is the rune here that does just that.
The bonus Movement Speed from Relentless Hunter is excellent for empower your ability to roam and find picks in the jungle with your [R].
The burst of heal from Triumph allows you to dive the back-line in teamfights and get out alive with enough health to keep fighting.
Coup De Grace's enhanced execute damage empowers your ability to blow up and finish off squishy targets.