In the early game past 6 you just farm, farm and farm. Don't forget to farm! Your first job in early is farm! Never forget to farm! If you are lvl 6 you could try to poke the enemy with Q + E and escape if you need with W. Just do this so much since he has 1000 Life. If he has 1k life you can engage. Use now your Q + E then use ur W and wait a bit, cuz the enemy will use all his abilitis to your Decoy. Then use again your Q + E and do your Ultimate. This should kill the enemy. If he has survived use your Ignite and he shall die. Since you have 2/0 on the toplane and the jungler isnt that much tanky you could try to kill the toplaner and the Jungler with your Ultimate and Q + E.

In the Mid Game your Job is to kill the enemy APC and ADC. This shouldn't be that difficult if you did well on toplane and have your Last Whisper and Tiamet. Just engage if the ADC and APC stay near and do your Ultimate. After your Ultimate went up you need to use ur W! Now you have 2 Options. If the ADC or APC survived you can chase them while you are invisible and execute one of them with your Q + E Combo or you went back and be safed.