Ignite is essential for lowering enemies below your R threshold.
Flash should only be used offensively chaining E+R/R+E.(See abilities)

Q+E+Auto = DH stack(R threshold)
R+E+Q = Ctrl+6

WARNING (HIGH OCTANE COMBO BELOW)
E+Flash+Q+Auto+R = gg ez

Pyke is all about chasing paper, why would you heal your "ADC" with relic shield when coins go straight into the bank account? Pyke does not farm minions, he farms champions.
Do NOT ever build past Nomad's, you only want Nomad for vision and bigger coin drops.
After Nomad go mobos for quick engage.
ALWAYS build Serrated Dirk first for the easy double kill potential.

Edge of Night > Youmuu's - Your mobility is already insane thanks to runes and mobos, Edge of night will make your 1v1 potential insane, and allows room for mistakes. Activate the shield, W, run up on an unsuspecting champion and delete them. Do NOT be afraid to marinate your food before you eat it, pull em around a little, dance around them while in W.
Death's dance will give you more survivability in team fights, hit the right combos let the team do their work, pull out heal, rinse and repeat.
You should never need to buy GA because at this stage in the game you should be in lobby. But, should you feel it necessary it'll allow your abilities do refresh and either help your team finish them off or dash away under the sea.

Do they have somebody fed with crit? Pyke does not have enough health at any point to eat crits Omens is ESSENTIAL if your team isn't doing enough damage and you need to hang in for one more ability cycle/autos to get them under R threshold.
Maw > Gage, Maw is obviously for MR purposes and Pyke at level 18 barely has enough health to pop a gage leaving him with around 200 health left if you manage to survive a burst. While Maw doesn't trigger of damage taken rather than health percentage.
Zz'ROT - THE MOST SLEPT ON ITEM IN THE GAME. Did your top laner feed? of course they did, if you're an offensive threat as you should be following this guide, do not be afraid to split push with Pyke, your mobility with this build is insane, and his E will clear a caster line and a Q will finish off the front line.

For ****s sake never go back in to save a stupid ADC and give them a double. BUT remember you can E away from a fight and go under, do not be afraid to get behind/next to a champion chasing your teammates and pull them away, OR get in front of them and dash towards safety to stun them.

Do not be afraid to use W freely, with presence of mind you should always be looking for the engage. W to get in range hit your CC, DO NOT GET CC'D, you used W in the first place to have the element of surprise, if their CC is down or you dodged it secure the bag with your E if not E out of the sticky situation.
You can E forward to have R in range.
You can R on top of them, E away, and then follow up with a Q while they're stunned to pull them back into the team.

Q+E+Auto = DH stack(R threshold)
R+E+Q = Ctrl+6

WARNING (HIGH OCTANE COMBO BELOW)
E+Flash+Q+Auto+R = gg ez

Flex on them with flash and the previous combos.

Offensive Pyke's take electrocute? Electrocute is the Iron man's Dark Harvest. Once DH is stacked a Q+E+auto puts champs under R threshold and they're dead before the stun is even over.
bUt AftERshoKc pYKE Is sSO GooD??? AFTERSHOCK PYKE IS FOR P U S S I E S. That's all I am going to say about that garbage keystone.
Sudden Impact adds to being a one shot machine, coming out of W or E on an unexpecting mage and watching them go through the paper shredder is god's work in play.
Relentless hunter and mobos make you a flying 1 shot machine, uncatchable, unescapable.
Presence of Mind is so that when you get that Penta with the constant reset of R, one you still have full mana, two you already have R again. Their top laner wants to split push??? Nah, paper shredder.
Tenacity will make it so you can bob and weave in team fights and make it easier to pull out with W.

PRAY TO LANE AGAINST MAGES. Yes, Pyke has no MR, but he doesn't need it because of his high mobility will never allow you to be caught by spells. Ex. The second a 500K+ mastery point Lux support misses her Q, know what happens? Into the meat grinder. Pyke is uncatchable, the only way you should die is if you mess up an engage. Jhin's CC + yours, and the burst capabilities of your abilities will make laning a cake walk. D R A V E N, This is my favorite ADC to play with because Draven is all about the fame and paper, just like you should be. Your R gives him his passive so not only does Draven receive full kill gold, but adoration stacks as well.