Queen of Pain + Witch Doctor

Why this works

Picking these two heroes together is a bet that their ultimates will somehow line up. The core issue is that they want opposite things from a fight. Witch Doctor needs enemies to be locked down in one place to get the full effect from Maledict and Death Ward. Queen of Pain, however, is a mobile assassin who blinks in, unloads her spells like Scream of Pain and Sonic Wave, and then repositions. She has a slow, but not the hard, reliable stun that lets Witch Doctor do his job. His own Paralyzing Cask is too random to be a consistent setup for her blink.

This often leads to disjointed teamfights. Queen of Pain will be looking for a pickoff on a support in the back, while Witch Doctor is trying to get his ultimate down on the enemy frontline. They both have high damage potential, but it's rarely focused on the same target at the same time without help. For the duo to really work, you usually need a third hero with a big, reliable initiation to hold everyone still. Without that, you're left with two powerful heroes who are often fighting their own separate fights, even when they're standing next to each other.