Wukong is melee damage dealer. He suffers his most damage out of his 1st ability (Nimbus strike) and normal hits. My guide is an offtank Wukong, with much HP and attack damage.

In early game you should try to only lasthit and farm a lot, getting money to afford big items like trinity force. Dont attack until you are level 3, have all skills, or there is a possibility for a kill. If u rush in too early you may die, and that makes u frustrating.
Be sure thats u harras the enemys hard, to make them unable to farm and lasthit. If you have strong enemies on your line (typpical Wukong killers: Vayne, Twitch) make sure to use your decoy spell wisely. You first rush at your enemies with Nimbus Strike, followed by a hit and a Crushing blow, and when the enemies have crowd control, u may run back fast enough with Decoy. If the enemies have surrounded you, u have to use an old trick to avoid being killed. Run in the direction of your Tower, then use Decoy, and run in the other direction while u are invisible. If u use it wisely, u can easily escape if u reach a bush, or you are wide enough away to teleport home.

If you have a supporter or a tank on your lane, make sure u get all kills and lasthit, because u need them more then they do. If you have a carry on your lane, do be too egoistic, and try to leave them some kills, becuase if you follow my build, you are an offtank, and they dont need kills as much as carries. Be sure to let no minion beeing killed by your minion, because if you farm good and have much creepkills, u can easily afford expensive items, and eather you and your carry own.

Your ulti is a strong weapon. If you reach lvl 6, you have not pushed too much (towerdive will end in death) and you and your mate are at least half hp, try to kill someone. Here you use your combo again. Rush with Nimbus Strike, Crushing Blow, and then Cyclone. Keep attention if the Enemies have great escaping spells like flash or ghost. Make sure u have your flash ready to easily chase them if they get out of your ulti. Maybe the enemies are too strong and kill you, you can easily escape. Cancel your ulti by clicking r (ultimate) again, and use decoy.

Midgame normally starts with the first teamfight. Keep attatention of the enemies, even if you have Warmorgs Armor. Let your tank initiate and do the classic combo again (Nimbus Strike, Crushing Blow, Cyclone). Try to use your combo to get behind their team and focus their Ranged Damage Nukes or their Supporter. But beware to not move too wide away from your team. If they will run back and you are standing in mid of the enemies, you will be dead.

If there is a good situation or you tank has not enough HP, you as an offtank are also able to initiate. If u have AoE ulties (crowd contol ulties are also very good) like Miss Fortune, Amumu, Katarina, Kennen etc., be sure to combinate your ulties, for a maximum of damage. If you do your ultimate, they enemies nearly always are able to run out of it. That will often split the Group and you can easily chase champions with low HP. But dont forget, stay near your team.

Wukong can still be killed by teams with much corwd control. Be sure that if you are low HP not take take too much of it. U can for eg. easily make xin push up your double (Decoy) or use it when malzahar gets in range. This is an easiy way to avoid death, and then used stuns etc for nothing. If the Crowd control gets too much, you can also sell your Berserkers Greaves, and buy Mercurys Treads.

In this gaming phase be sure to kill as much towers as possible. You as an offtank are able to tank them if necessary, and u can use Crushing Blow on Towers. But be carefull if the enemie team is miss, and do better go back instead of daying. If you die, your team will maybe use the next teamfight without you, and that could cost the win.

As an Offtank, you should buy both damage and tankitems. But your items still depends on the enemie team. If many of them Buy madreds bloodrazor, you should buy some resistance instead of max HP. Instead of Warmorgs armor, Thornmail will be very good. If the enemies got much resistance, maybe think about to sell bloodrazor and buy a blackccleaver or last whisper for armor penetration instead. Your ulti Deals as more damage as your attack damage rises, so be sure to have some strong attack damage items if u want to play less offtank, and more damage dealer.

You can choose between 3 summoner spells. Ignite, exhaust and flash. I always play with flash and ignite, ignite is for enemies who have lifesteal spellvamp or any form of heals, but exhaust is also very good in teamfights. Be sure to always use exhaust for reduced damage not for slow, because if u have frozen mallet, or Nimbus strike, you are able to chanse them without wasting exhaust. Flash is also very good, you are able to escape in situations you would die, maybe if u use Decoy and you are reaveled.