Earthshaker + Shadow Fiend

Why this works

Setting up a perfect Requiem of Souls with Fissure can be awkward. Earthshaker wants to cast his stun from a safe distance, but for maximum damage, Shadow Fiend needs to be standing directly on top of the target. This mismatch in positioning means the combo requires a lot of coordination to pull off correctly. If Shadow Fiend tries to walk into position after the Fissure hits, the stun might wear off too soon. While a Blink Dagger into Echo Slam is a much cleaner setup, that relies on a long cooldown and a key item timing that isn't always available.

Both of these heroes can have a slow start to the game. Shadow Fiend needs time to build up souls and farm core items, and Earthshaker isn't a huge threat until he gets his own Blink Dagger. This shared need for farm can create a passive period where your team gives up a lot of map pressure. If the enemy team is aggressive, they can take control of the game before this duo even gets a chance to come online. By the time Earthshaker and Shadow Fiend are ready to fight together, they might already be playing from a significant deficit.