So far Riot is doing a huge over hall to all ADC's. All they have done to Varus is give his ult 3 stacks of blight. So......it does 6% of health as extra damage once. Hitting with that ult basically already ensured you were going to get those stacks anyway, and the stacks stop at 3....so I don't see ANY buffs here.
I think you need to look at his passive. It feel it's basically useless to his feel as a marksman champ and a defender. Perhaps increased damage or longer range when by your own turret would have a more meaningful effect in the laning phase ( just throwing things out here ). He definitely needs some changing and adjusting though.