Snowballing reset and maximum damage potential.
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 takedowns grant permanent cooldown on your Ultimate.
Improved attacks and sustained damage
Takedowns restore 20% of your maximum mana and refund 10% of your ultimate's cooldown.
Takedowns on enemies grant permanent Tenacity.
+6 AD or 10 AP
+5 Armor or 6 MR (match-up)
Pyke easily able to proc the extra burst damage from Electrocute with a [Q]->[E]->Auto or [R] for massive burst and setup for an [R] execution.
Pyke benefits massively form the extra Lethality after casting [E]'s dash for extra damage and execution setup.
Pyke is naturally a snowballing assassin and as such relies heavily on his ability to snowball and actively pick up kills. Eyeball allows you to further push that into a bigger lead.
More [R] casts means more kills and more gold share with your teammates so that you can easily snowball the game to a victory.
Presence of Mind is huge for keeping your [R] on a short cooldown. Mid Pyke is all about those huge executions with [R].
Tenacity on Pyke mid can be the difference between a pentakill with [R] and dying instantly. Pyke needs to be able to get to his targets to be useful.