As soon as you get second upgrade for 1 (35% more dmg), be very aggro in lane. Look for ganks/fights when ult off CD with team. As soon as you have 3 max upgraded you should fight with your team even without ult. Get close with mobility/Warp to get kills. After Siphon you can teamfight until the game ends. Superior CD is better for overall build, while Duration is better if you go more sup route.