More Shaco Rework Ideas
(This list doesn't include many of the respective nerfs that would be necessary.)
Q (Deceive) - Ideas include: A. Giving the cloud of smoke an effect, like a short blind or vision impairment (Graves/Nocturne). This would slightly help escape against pink wards/oracles, and keep to his theme. B. Adding another cloud of smoke when reappearing, maybe having an effect like the one mentioned above. This may help put damage on targets with bodyguards, or help to fight against better nuke champs and duelists. It also makes more sense thematically than a clown appearing out of thin air. C. Lowered cooldown on kill/assist. This is more in tune with his sweeping playstyle, and alludes more to an elusive acrobat. His playstyle would be more akin to Katarina/Yi than to Rengar. D. New active called "Surprise." While stealthed, press Q on an enemy to drive 2 daggers into them, dealing increased damage. This change might open up new burst mechanics, making him less crit reliant, or moving his crit elsewhere.
W (Jack-in-the-Box) - Ideas include: A. Remove the invisibility, but make an actual box, with good defensive stats, until the Jack pops out. This let's it be placed more easily in fights, makes them less frustrating, makes more strategic demands, and makes more real-world sense than invisible boxes. B. The Jack no longer attacks, but pops out laughing, spewing laughing gas. Enemies are feared and suffer armor reduction. Maybe make the gas toxic to neutral monsters and minions, something to keep its jungling uses. C. The Jack has better defensive stats, projectiles shred resists with each consecutive hit. D. The Jack instead deals scaling AD. They could even represent miniature Shaco's throwing little daggers.
E (Two-Shiv-Poison) - Ideas include: A. Throw up to 2 daggers, since he wields 2. The damage is now physical. The first cripples, slowing the enemy a bit and making them bleed. The second can be thrown 1 second later, at a different target for the same effect, or at the same target to increase the slow and have its damage critically strike. B. Daggers are coated in a more potent poison. Consecutive hits amplify the poison, adding increasingly potent magic damage, and an increasingly potent slow (this could also be another idea for Jack-in-the-Box consecutive hits). The thrown knife drives the poison deep, acting similarly. After the base damage, the poison and slow ramp up over 4 seconds (Nasus' Wither mechanic, but much less harsh). Dagger itself scales with AD, poison and slow scale with AP. C. Daggers are coated with a weakening poison that reduces enemies' damage. This actually lets him get more auto-attacks off, and let's him have more utility in team fights if he decides to build tanky. D. Daggers coincide with Deceive, through a passive called "Showmanship". Each thrown dagger reduces the cooldown of deceive by 1 second. These daggers would likely have lower damage and cooldown, maybe even longer range at the cost of their utility.
R (Hallucinate) - Ideas include: (Firstly, update clone AI with some quality of life buffs. It can still feel clunky sometimes. Maybe adjust it to pursue targets into Fog of War. Also, make it controllable even if Shaco dies, and make clone explosions scale with AD) A. Using your ult splits you into three, in a fixed triangular formation. A couple more times over a few seconds, you and your clones will disappear and reappear in clouds of magical smoke (which perhaps have the debuffs aforementioned for Deceive), trading places with one another, unless you press R again to enact free-movement. B. You make a copy of yourself that cannot be controlled, but mirrors everything you do with lower damage, and can be attacked. The active smoke gives debuffs. C. You make a clone of yourself, which retains 75% of your stats. This can still be controlled by alt+clicking, but pressing R again splits you and your clone again, so that there are 3 Shaco clones, which each retain only 25% your stats. All clones do full damage when exploding. D. Over the course of 10 seconds after initial use, you can use hallucinate up to 2 more times. Spawning a new clone makes the previous one explode.
Passive: This should be decided after all of his skills are figured out, so it can be made to compliment them. Maybe toy with ideas of other champions, like Viktor's augmentor, letting you even choose if you want to focus on a specific ability, alter its use, or even decide if it will have AD or AP elements. This could be a way to let AP Shaco players choose to play that way as the match begins.