Shadow Shaman + Viper

Why this works

Thinking this duo guarantees a kill on a single target often overestimates their burst. Shadow Shaman provides long-duration lockdown with his disables, creating a window for Viper to apply stacking slows and corrosive damage. A hero caught in Shackles is an easy target for Viper to right-click and wear down. However, the damage from both heroes is applied over time, not instantly. If the target is durable or receives help from a teammate, they can sometimes survive the full duration of the lockdown and escape before Viper’s toxins can finish the job.

This translates into a lane that can punish mistakes but doesn't dominate by default. A successful gank requires both Shadow Shaman and Viper to be in position, and it relies on Shaman's long cooldowns. Later in the game, they are effective at picking off a single isolated enemy to start a fight with an advantage. The problem is that both heroes are relatively slow and fragile. If the enemy team sticks together or initiates on them first, their single-target plan falls apart completely, as neither hero is great at playing from behind or repositioning in a chaotic fight.