Earthshaker + Primal Beast

Why this works

Seeing these two heroes on the same team might look like a free win with all their stuns, but their combo isn't always clean. In theory, Earthshaker can drop a Fissure from long range to create a perfect setup for Primal Beast to land an Onslaught charge. The issue is that both heroes are natural initiators who want to go first. If they aren't on the same page, Primal Beast might charge in right as a Fissure wall goes up, blocking his path entirely. Their ultimates also stack area-of-effect control, but without coordination they can easily be layered on top of each other, wasting a lot of lockdown duration.

The success of this duo really depends on which player is willing to play the setup role. If Earthshaker consistently uses his abilities to catch enemies for Primal Beast to run at, they can dominate. If they both try to start fights independently, they'll find their spells overlapping and targets escaping. The lane and mid-game ganks are a toss-up; sometimes they'll chain-stun a hero for an eternity, and other times they'll get in each other's way. It's a partnership that requires communication to work, which explains why it doesn't consistently produce great results.