Wukong changes - one can dream.
I have one tricked
since I started playing LoL back in S5. I have about 800k mastery points with him. He is a balanced champion over all I would say, but I think he is still very lacking in certain areas. I understand you can't just buff champions, but the suggestions aren't too bad, and just add some more value to his very dry kit.

****PASSIVE: Stone Skin **** "4 / 6 / 8 bonus armor and magic resistance for each visible nearby enemy champion"
This is decent later in the game in team fights. It is very lacking in the early game compared to other passives. The gold value of this passive is very small. Most champions have more established passives. Wukong's passive comes from Sun Wukong's lore "a monkey born from a stone". I suggest this change:
"6 / 8 / 10 bonus armor and magic resistance for each visible nearby enemy champion with a max stack of 4. While Wukong's health is below 25% his bonus armor and magic resistance is doubled."
increasing the bonus resistances but lowering the max stacks by 1 means it is just slightly stronger early game, but remains the same later in the game.
  
****Q: Crushing Blow ****
"10 / 15 / 20 / 25 / 30% of target's armor" for 3 seconds.
Make it last 5 seconds. This one is not a big deal, it just helps his 1v1 potential, mostly.

****W: Decoy **** " invisibility for 1.5 seconds and leaves behind a decoy"
This is a great ability, I just wished it did something more. Here is a quote from the real Wukong lore:
"He knows spells to command wind, part water, conjure protective circles against demons, and freeze humans, demons, and gods alike."
My suggestion for change here would be more for wave control, and jungling, so it is subtle. I think the following should be added to this ability:
"All non-champion targets hit by the clone are stunned for 1 second. If an enemy champion is hit by the clone, Decoy's cooldown is reduced by 0.5 seconds per champion hit."
  
****SKIN****
Another quote from the real Sun Wukong's lore:
"Wukong defeats the dragons of the four seas in battle and forces them to give him a golden chain mail shirt, a phoenix-feather cap, and cloud-walking boots."
Dragon Slayer Wukong? Why not? It is in the real Wukong's lore.