Doom + Viper

Why this works

Trying to kill a priority target can feel inefficient. Doom's ultimate is a complete shutdown, taking one hero entirely out of the equation. Viper's own ultimate, Viper Strike, also provides powerful single-target control with its slow and damage. The core issue is that stacking these abilities on one enemy is redundant. A Doomed hero is already disabled, so adding Viper Strike on top is often overkill. This means you're either committing two major spells for one kill or splitting your focus and risking neither target dying fast enough.

This pairing creates a one-dimensional strategy that relies on getting pickoffs. A smart opponent will recognize this and force grouped-up fights, where the single-target nature of both Doom and Viper is a liability. Without strong area-of-effect damage or control from these two cores, fighting into a deathball is difficult. The enemy can often afford to trade their Doomed player for a better fight, or use a save item to negate the gank entirely, leaving your key spells on cooldown.