So i suspect you are there because you want to learn to play Pyke on his real potential, what mean jg 1000ap one shot..just joking. Well for first you need to know more about that champion and decide if it fit your style or not. Pyke is first official support ad (if we don't count Yasuo) which really work with most of ad items, anyway you must need, even if he can go crazy ad and all those, Pyke is extremly mobile but his 1v1 is weak so Pyke need also someone to even clean his work or to hurt everyone, and then you clean all with your ult. I can't say you can't play him on solo lanes, but is better on support role, or jungle, his clean as jungler is really good you should try if you cant like to support.

Ignore eveything i wrote belown here, check runes up thank you very much.
I will update that part sometime in future

Resolve are probably best runes to play as support, you cant trigger Aftershock even with Bone Skewer or Phantom Undertow, Bone Skewer also trigger Font of Life which will sustain more your adc and team in a fight. Conditioning will also help with your leack of tankiness, but if you plan to go ad and dont buy at all armor better choose Second Wind. Revitalize will provide more heal you and your adc from relic shield, but if you want more 5-6 ad you can go for Overgrowth

as side you can choose the classic precision for Triumph or Inspiration in which case you will want Perfect Timing and future market but any combination of [[insipartion] can be good in some situations.

Also if you are more like an all-in player you can play with these runes are not so bad, but aftershock have more versatility.

LETHALITY, BUILD LETHALITY AND NOTHING ELSE, THATS WHAT RITO WANTS, THATS WHAT RITO DID WITH THAT CHAMPION.

	Duskblade is one of my favorite lethality items, and a great core item on pyke. The first passive allow you to deal more damage with your first basic attack after you was unseen for at least a second, that is pretty easy to proc with your W or just going in a bush
	a nice lethality item, bseide flat stats gives you some passive ms and an active which increase your movement speed for few seconds, making it a great ingage, execution or even escape item
	Beside the lethality and health (which will be converted in ad) edge of night have an active which grant you a spellshield after a second, making it harder for enemies to stop/catch you with a hard cc from start
	Best defensevie option for any ad snowball champion, assasins or ad carry in general
	Death's Dance makes you more tankier, getting some of damage over time, not instant, and grants you lifesteal, also 80 ad is the greatest amout of ad you can get from a single item (ignoring that troll item from nexus blitz)
	Ninja tabi are a good defensive option against most champions based on spamming basic attacks, or just some free armor to defend yourself
	Mercury is a good item against team comps with a lot of cc lowering the duration of all cc you would get, also grant some magic resist.
	Boots of mobility are a good roaming and snowballing option, also can create some pressure on map being easier and faster to travel on map

	In early game you will need most of time Bone skewer even to poke, pick a target or start a fight, especially if enemy support will be a ranged, wich will make hard for you to get close enough to use other skills. Think at this skill like at Thresh's Q more a lot more slowly to use and your enemy can dodgemore easy, the best way is to use it when enemy can't react, when is stuned, distrated or just don't see you. Also if you are close enough and/or want just a lil poke you can just pres Q without holding it, that way you will not drag him, but will do more damage, and the slow effect will be applied too.
	You can use Ghostwater dive in a lot of ways, to roam, escape from a hight, and to get close to your enemy, or just to go faster in a certain area. In most of cases after active Ghostwater Dive you will want to use Phantom Undertow to stun your enemy, but if you can't get enough close better pick him first with Bone Skewer then use your E.
	Phantom Undertow is a dash, which stun all enemy positioned between your original position (before dash) and your actual position. Except the obvious stun enemy usage, you can also use this skill to jump over walls, escape (which is a lot effective cause enemy can get stuned if not pay attention on his position) and.. i forgot last one sorry.
	Death from below is probably most important skill from Pyke kit, a skill which can execute enemy, the last one which assist at the kill get full gold from it and the ult got a free reset for 20 seconds, the reset get a reset too if you execute someone. I think is important to note, you can't use it as escape, the dash work only if you hit a enemy champion with it.

Would be good to mention you can use Flash both when you cast Bone Skewer or to secure your stun from Phantom Undertow.

You max first Q Bone Skewer for both cooldown reduction and damage incresing, then max
W Ghostwater Dive cause the movement speed incresed from that skill will help you to roam faster or just catch your victim. it is not worth to max E Phantom Undertow cause the cooldown is the same and the extra stun time is basically null in early fights. you can max Phantom Undertow second if you want, but i think some extra movement speed have a lot more use than 0.1 extra stun.

When most melee supports are tanky, Pyke is a extremly squshy one, which can make him a target as viable as your adc, bascailly you have sustain from your passive, but in a fight or when enemy have vision on you that sustain is useless so you must be extremly careful early game.

With Pyke you can play either aggresive and bully your opponents or be an afk fisherman which wait the perfect moment to catch his prey. So if you can't do many things in first minutes of game just wait until you get level 6, then you can be a threat, but until that don't forget, even if you are a support-assasin, you're still a support in first place, so don't forget to ward river, the dragon and the bush close to your lane, which can be used as opening for a gank. I'm not good at explaination, you can learn from any sources how to ward, but basically in minute 3 you will want to have at least a ward placed.
So that is extremly important, if your adc just recalled and you have no reason to, or idk nothing is happen on your lane, or the adc sucks and you lost the hope in humanity don't just stay afk behind turret, always be searching to roam, Pyke have high potential to do with his kit and mobility, you must use every free second you have to help your team.