Outworld Destroyer + Viper

Why this works

Picking both Outworld Destroyer and Viper often creates a draft that's easy to play against. Both heroes excel at dealing sustained magic damage from the core positions, meaning your team's damage output becomes very one-dimensional. This allows opponents to itemize efficiently, with items like Pipe of Insight or even early Hood of Defiance on multiple heroes heavily mitigating the impact of two of your main damage dealers. The core problem is this redundancy; they fill a similar niche without covering each other's weaknesses, particularly against magic immunity.

The laning stage might feel stable, but the composition shows its cracks in mid-game teamfights. Enemies with Black King Bar can effectively ignore both heroes for a crucial duration. While an Astral Imprisonment can set up a target inside Viper's Nethertoxin, this interaction is often too slow and doesn't solve the fundamental issue. Outworld Destroyer needs a target held down to unload damage, and while Viper provides strong slows with Viper Strike, he lacks the instant lockdown to enable that. The pair ends up feeling awkward, often lacking the physical damage or hard initiation needed to close out games.