Mars + Pugna

Why this works

Drafting these two heroes together creates a fundamental conflict of purpose. Mars excels at trapping enemies with Arena of Blood and beating them down with physical attacks. Pugna, on the other hand, contributes through magic damage and his utility spell, Decrepify. The core problem is that Decrepify, whether used offensively to amplify magic damage or defensively to save an ally, makes its target immune to physical attacks. This means that in the heat of a fight, Pugna can accidentally save the enemy that Mars has trapped, completely negating the setup. Their damage types are split and their core abilities can actively work against one another.

This awkwardness plays out in mid-game teamfights. When Mars commits his ultimate on a key target, the follow-up from Pugna is often clumsy. A well-timed Life Drain on a speared hero is effective, but if Pugna tries to use Decrepify to secure the kill, Mars is left unable to contribute any right-click damage. This forces Pugna to play much more passively than he'd like, holding his spells and reducing his impact. Enemies who get caught can often survive because the damage isn't focused, and they know that a single defensive item can isolate Mars from any of Pugna's magical support.