Talon falls off late game if you can't excel in the early game. Talon is a master assassin, so you want to poke before closing the gap to pick up the kill. If needed, grab some mana pots, you might need it. Hit your enemy with rake as much as possible, then close the gap with cutthroat, and utilize his passive.

About this time, you should have taken the top(or mid) lane tower out, so you should start to roam. go to the different lanes and pick off the APC and the ADC. It feeds you, and shuts them down. Sometime soon team fights will start to break out. Jump in with u E, hit as many as you can with rake, hit the adc(or APC) with a basic attack and quickly hit your Q. pop your ult and its done.

Continue picking off the weaker enemies, and get fed. Everything comes easly after that. Push all the lanes you can as far as you can, utilize the fact the when u hit his Q, it resets his attack timer. With it, it will allow you to do massive dmg to both towers and enemy champions. All thats left is to push it all the way to their base and win.