Shaco rework Idea
Passive(Masquerade) :Teleports to the target allied champion (550 range) and takes on their appearance for 30 seconds. The disguise includes the target's current health, mana and emotes. The disguise is broken upon casting a spell or attacking, or upon your or the disguise's health being dropped to 0. 90 second cooldown.If you kill an enemy you may also masquerade as them for the rest of the game without having to teleport to them. (yes it is basically an upgraded Tricksters glass effect)
Q(Jest)-ACTIVE: Shaco instantly blinks to the target location and stealths for up to 3.5 seconds gaining bonus movespeed while stealthed. his next basic attack within the next 6 seconds will deal bonus physical damage if Shaco attacks the target from behind. Refreshes whenever a Target affected with Dirty Trick's poisen dies.
W(peek-a-boo)-ACTIVE: Shaco summons a box at the target location that stealths after a 2-second delay and lasts for up to 30 seconds. If an enemy springs the trap, it opens fearing the target who triggered it and attacks the single closest target ONCE applying a slow and magic damage .Multiple boxes deal reduced damage
E(Dirty Trick)- PASSIVE: Shaco's attacks deal bonus magic damage and poison his target, causing them to take additional magic damage over 4 seconds. Subsequent attacks refresh the poison's duration.
ACTIVE: Shaco tosses a concealed shiv at his target dealing damage and applying poisen. The damage is increased if the target has thier back turned upon impact.
R(CarnEvil)-ACTIVE: Shaco vanishes for 0.5 seconds, then reappears creating TWO clones of himself(Tragedy and Comedy) that live for up to 10 seconds each. One clone(Comedy) deals 150% of Shaco's damage but TAKES 50% more damage whislt the other (Tragedy) DEALS 50% less damage and cannot apply on hit effects. Upon reaching 40% of thier maximum HP Tragedy explodes into Knives dealing high magical damage to nearby targets. Comedy instead explodes into confetti (which does nothing).
Summary: This rework aims to add more tricks and mind games to Shaco's repertoire. One of the current problems with shaco is that when he gets far enough ahead he no longer has to rely on outplaying his opponent or using the full extent of his kit to achieve his kills. A simple decieve into two-shiv Ignite will finish off most opponents. I believe this is what makes Shaco more problematic and a bit too snowbally at lower level play. This kit is based at giving opponents more of a fighting chance by directing shacos kit from stabby stabby to more tricky tricky. First we are seeing a shift from AD shaco to more of a AP focused shaco which means In order to get the full effect of his kit players will have to find ways to get opponents to activate boxes, kill his clones or if agains particularly clever opponents simply use hit and run tactics with his Dirty trick ability.
Ganking: needless to say ganking is where Shaco truly shines. proper use of masquerade to get into position can be vital to a successful gank and once a gank or two goes off your options of WHO you may masqurade as begin to increase (thus Shaco snowballs in utility not just power)Also after a successful kill Shaco may easily slip out of view
In teamfights: Teamfighting was always one of shacos weakpoints and most resigned to opting out of teamfighting alltogether and instead focus on split pushing. This kit aims to solve that by his Ultimate which will know create THREE Shaco's instead of two. Each clone has a unique goal in a fight. Comedy will have deceptively high damage output thus making it hard to identify the real Shaco whilst Tragedy's goal is to soak as much damage as possible so that he explodes and deals high burst. more clones also means you effectively have more "sandbags" to absorb attacks and spells for you thus increasing shaco's lifespan.
New Lore pitch EXTREMELY rough draft
Shaco isnt a person but is instead a malevolent entity (similair to Aatrox or Tahm Kench) who represents mania and the general crazed way or the world. The entity possesses the bodies and spirits of insane or crazy people(maybe Asylum inmates or Mad scientist) slowly turning them into a surrogate body of sorts to act as his "Jester" which is basically person who can channel a portion of his power. The demon or his "Jester" collects souls of his victims in the forms of mask thus allowing him to take on his victims appearance.Shaco does not follow a real pattern how he chooses his victims seems to be completely random and only based on whatever the demon would find most amusing. young or old , Nobleman or cutpurse it really doesnt matter all can be added to his "collection". Almost all of Shaco's kills are premeditated as Shaco delights in seeing his victim panic and squirm to the point of near insanity thier twisted faces in thier final moments are key to making the perfect mask's.
tl;dr think a mixture of "the many-faced god" from GoT + Brand