Does Shaco need a rework? What if, hypothetically speaking... All feedback ( Rioters too ) welcome!
Before I begin I ask that you forgive my low level; I'm a player who recently returned to LoL after many of their recent changes and have begun from scratch. All potential changes on this post are hypothetical ( they are "what if/why questions/statements" ) and based on my thoughts regarding Shaco. Feedback from the community ( Feedback being what is like, disliked, things you would change/why and community being all players and Riot employees ) is not only welcomed but encouraged.
When I thought of 
and the people who played him well back in the day I always remember appreciating his kit for being unique/feeling a bit of frustration over never being able to make use of the Backstab passive and respecting those few players who could dominate with Shaco. When I look at Shaco now days I think to myself that Fiora's rework, whether Riot meant to do this or not with the rework, has tarnished Shaco's uniqueness by not only giving Fiora a similar goal ( strike the foe from their weak side ) but by giving her a kit that allows her to do it much better than Shaco ever could. I feel it leaves him competing Kha'Zix a little too much ( Shaco dominates foes from their weak point while Kha'Zix dominates foes when their alone ) and because Shaco is now more than ever in an awkward spot between Fiora and Kha'Zix ( kinky, right? ) I feel a rework is in order, albiet not a very drastic one.
My thought, given Shaco is supposed to be this fearsome fellow ( "He is a terrifying figure, typically shunned by both his fellow champions and the media at large." - Shaco's Lore ) is that his kit should be reworked around the crowd control type Flee ( http://leagueoflegends.wikia.com/wiki/Flee#Flee ) and thus giving Shaco more of a horror-theme while giving his kit a unique edge.
Skills below are in the format of "Skill button: skill name; description & why I feel this should be as listed."
Passive: Sadism; Shaco enjoys tormenting his victims and deals 10% + critical strike chance × 1 + bonus critical damage % ( the same as Ashe ) bonus damage with his blades ( basic attacks from him/his clone and two-shiv techniques ) when striking an enemy filled with fear/flee.
I feel the name and changes to his passive, thanks to his lore ( "Most would say that death isn't funny. It isn't, unless you're Shaco - then it's hysterical. He is Valoran's first fully functioning homicidal comic; he jests until someone dies, and then he laughs." ) fit in with what should be in his kit given he is clearly a sadist. It is also worth noting his current passive, Backstab, has him doing 20% bonus damage when striking a foe from behind but I feel a new number may be needed given my hypothetical change to his passive.
Q: Spook; Shaco instantly blinks to the target location and is granted 30% or 40% movement speed + Stealth for 3 or 4 seconds or until his next basic attack or use of his Two-shiv Techniques use. Attacking a foe with either basic attacks and/or Two-shiv techniques while stealthed breaks the stealth, applies Fear/Flee for 0.5 / 0.75 / 1 / 1.25 / 1.5 seconds and deals an extra 10% + critical strike chance × 1 + bonus critical damage %. Cost: 90 / 80 / 70 / 60 / 50 mana, has 400 range and an 11 second cooldown..
Shaco is supposed to be a scary assassin but the only current part of his kit that causes fear/flee are his Jack In The Boxes; not a lot for him to work with considering what his thematics suggested of him. On top of this, he does not get to assassinate much late-game because his kit currently makes it hard for him to teamfight ( at least this was how he was viewed back before I had left the game ) and I feel this needs to change to make him healthy for the game. This skill, originally titled _Deceive, _had Shaco instantly blink to the target location and stealth for up to 3.5 seconds, also causing his next basic attack within 6 seconds to critically strike for -60 / -40 / -20 / 0 / 20% bonus critical damage. I feel by reducing the time he has to activate the bonuses from his Q but giving him a little more time in stealth/a speed boost him teamfighting becomes more realistic because he should be able to make it to his foe's backline from his backline a bit easier. You also gain more of a reward for successfully reaching their backline given you could disrupt their soft-targets with your Flee whilst chunking and/or killing them. Shaco would need to be careful though as he could still be countered and/or spotted by vision wards, sweepers, etc.
W: Jack in the Box; Shaco summons a trap ( a Jack in the Box ) at the target location that stealths after a 2-second delay and lasts for up to 60 seconds. If an enemy springs the trap, it opens and causes surrounding enemies to turn and fear/flee while it attacks nearby enemies for up to 5 seconds. Flee Duration: 0.5 / 0.75 / 1 / 1.25 / 1.5 seconds, Magic Damage Per Attack: 20 / 40 / 60 / 80 / 100 + 20% AP, trap attack speed unchanged. Cost: 50 / 55 / 60 / 65 / 70 mana, 425 / 300 range and a 16 second cooldown.
The average/inexperienced Shaco player ( compared to a more knowledgeable Shaco main )really only thought two things about his Jack in the Boxes: they were good at tanking small sums of damage ( monsters at jungle camps for Jungle Shaco, minion damage to help protect/last hit under towers for lane shaco ) and defending ( covering his retreat as Jungle Shaco, protecting himself from ganks as a lane Shaco ) himself from potential threats. With Shaco's reworked passive being triggered by Fear/Flee Shaco can now set up easier ambushes capitalizing on the bonus damage. I feel this newfound utility from his Jack in the Boxes helps Shaco be a healthier champion.
E: Two Shiv Techniques; Shaco passively targets his foes limbs with basic attacks, slowing their movement and attack speed by 12 / 14 / 16 / 18 / 20% ( multiple attacks do not stack the slows but instead reset the duration ) and causing lesser beings ( minions and monsters ( excluding Baron Nashor and the Dragon ) a 20% chance to miss him when they attack for 2 seconds. Activating the ability causes Shaco to throw his Shiv at his current target's leg dealing 25 / 50 / 75 / 100 / 125 + 100% AD/AP damage and slowing his foe's movement speed by 40% for 4 seconds. Cost: 50 / 55 / 60 / 65 / 70 mana, has 625 range and an 8 second cooldown.
This skill, based off of current Shaco's Two-shiv Poison ( passively causing Shaco's basic attacks poison his targets, slowing them for 2 seconds and causing minions and monsters to occasionally miss their attacks ( a slow of 10 / 15 / 20 / 25 / 30%; minion and monster miss chance at 20 / 22.5 / 25 / 27.5 / 30% and doing 50 / 90 / 130 / 170 / 210 + 100% AP + 100% bonus AD magic damage ) was his bread-and-butter for safe camp clearing and magic-based Shaco. I'm afraid that if I left the skill as-is it would make Shaco a bit too strong given Shaco's new passive and thus I decided to lessen the numbers of his movement speed slow/miss rate/damage. To make up for such a drastic change though I decided to give Shaco's skill the ability to also drop his foe's attack speed.
R: Hallucinate; Shaco vanishes for 0.5 seconds, then creates a clone of himself that lives for up to 16/18/20 seconds and explodes upon its death, dealing 300 / 450 / 600 + 100% AP magic damage and 0.5 / 1 / 1.5 seconds of Flee to all enemies caught in the explosion. Shaco's clone would keep it current stats.
Shaco would primarily be play as an assassin in game, focusing on his ability to capitalize on his Fear/Flee. As a laner in the early game he would be best suited to mid/top and be able to roam early; also able to use his Jack in the Boxes to cut off junglers from ganking his lane, leaving his side of the jungle if his jungler were to wind up in a skirmish on his side of the map or to cover his jungler's escape from the foe's side of the jungle. As a Jungler Shaco would set his boxes up at the camp(s) of his choice before camps would spawn/rely on the passive of his Two-shiv Techniques in order to preform clears with minimal damage. Jungle Shaco would also be able to sneak into lanes behind the opposing laner(s) to set up his boxes to garen-tee successful ganks.
When the midgame/lategame roll around he would capitalize on either split-pushing or setting up ambushes for his team with boxes on over-extended foes; his boxes being able to cut off their escape while he and his team dived upon foes. His goal in teamfights is to disrupt the enemy team while going for their carries by using Spook to sneak into the backlines and then attacking a mage or marksmen to proc his Q's Flee while being able to cause havoc by dropping his boxes and his clone. If Shaco has been paired with others that use hard CC he should be able to do a fair bit of damage before escaping or re-positioning to attack again with Spook. At this point in the game he will either have very high burst damage from being built AP or high sustained damage from having built AD.
Sated Devourer, Runeglave and Warrior are strong items on him: Sated Devourer would let him apply even more damage to foes under the effects of Fear/Flee while Warrior and Runeglave would both give him the CDR he needs to trigger his Spook and Jack in the Boxes quickly in fights. Shaco will benefit highly from CDR but Critical strike and/or on hit or AP items depending on playstyle are encouraged.
And that's pretty much it; thanks for taking the time to read this assuming you did take the time to read this. My sources were from the League of Legends website and the League of Legends wikia.
