How to counter Viper

In lane

Phantom Lancer
• Viper's damage is single target and he is unable to deal with Phantom Lancer's illusions. • Phantom Lancer can easily close the gap with Phantom Rush and then overwhelm Viper with illusions. • Viper Strike can be easily dodged with Manta Style or Doppelganger.
Windranger
• Considering that Viper is a very slow hero, he easily gets outrun with Windrun. • Windranger can outrange Viper with Powershot. • Windrun can be activated to dodge his powerful Poison Attacks.

-50% Viper Strike Mana Cost / Cooldown
25
Nethertoxin Radius increases by 25 every 0.5s
+0.35 Predator Damage Per Missing Health
20
+70 Viper Strike DPS
+15% Poison Attack Slow / Damage
15
+20/40 Nethertoxin Min/Max Damage
+15 Corrosive Skin Damage Per Second
10
+1s Viper Strike Duration

At level 1, before items.

Damage

48–50