I think we need to look at Varus' Q damage compared to basic attacks. He needs 2 seconds to use his Q. He can basic attack about two times if he wasn't channeling this. Lets say he has exactly 100 attack damage for this situation.
If he channels and uses the Q after channeling for the full duration, Varus deals (with 100 AD): 235 + 160 = 395 Physical Damage
If he basic attacks twice (at least) instead, he deals: 200 = 200 Physical Damage
This does not include any damage coming from his W. Varus needs to get stacks of his W on his target to be meaningful in battle, but his entire kit is about staying at a distance which is closed when he has to basic attack an enemy. I suppose a change to his W since his Q does deal great amounts of damage if it directly hits an enemy. I also think the reduction per unit hit for his Q should be decreased since it is incredibly huge compared to other piercing abilities. Finally, his basic attack range should be increased to match his play style of "the hidden arrow that is about to come out of no where and kill you" type of archer.
Basic attack range increased to 625 from 575
W- Blighted Quiver
Reworked
Varus' concept of a long range, hybrid, ability Marksman is hampered by his need to basic attack his targets. Due to this, his ability's should apply Blight as well and all Blight stacks be consumed at 3 to deal the bonus magic damage. His basic attack range should also be increased to match his concept and play style. The bonus magic damage on basic attacks may or may not still be applied.
- Varus' basic attacks apply 1 stack of Blight. Upon reaching 3 stacks, the marks will be consumed, dealing 6/9/12/15/18% of the targets health in magic damage
- Varus' abilities now also apply 1 stack of Blight, but the amount of stacks applied can be increased based on the ability's method of increasing the stacks.
Q- Piercing Arrow
It didn't feel good enough to 360 snipe a target with a huge, fully charged arrow so Piercing Arrow should be able to be fully charged amd proc 3 stacks of Blight to automatically be proced and deal the extra damage. It also now deals more damage if 2 minions counter you in lane. The base damage is also decreased due to this huge buff in damage when fully charged.
- Now applies 1 stack of Blight. After 1 second of channeling, it will apply 2 stacks of Blight. After 2 seconds of channeling, it will apply 3 stacks of Blight and immediately proc the stacks to deal the maximum health damage.
- Damage reduction per enemy reduced to 10% from 15%
- Minimum damage increased to 50% from 33%
- Maximum base damage decreased to 15/60/105/150/195 from 15/70/125/180/235
E- Hail of Arrows
Similar to Piercing Arrow, Hail of Arrows applies Blight in it's own way. Varus can now have a reason to try and trap ANY enemy inside his desecrated ground through his ultimate or anything else. To compensate for the big buff, the slow has been slightly nerfed to avoid really overpowered situations with immobile carries.
- Now applies 1 stack of Blight. Enemies inside the desecrated ground are now applied 1 stack of Blight every 1.5 seconds.
- Slow decreased to 15/20/25/30/35% from 25/30/35/40/45%
I think this should be what Varus should be looking to do in lane. Lane bully the hyper carries out of lane by shooting deadly arrows at them.