Axe + Bane

Why this works

Setting up a clean Fiend’s Grip is the whole game. Once Axe gets a Berserker's Call on one or more heroes, Bane has a completely free window to channel his ultimate on the highest priority target. No one can interrupt him because they're all taunted. This combo deletes the main weakness of Bane's kit, turning his vulnerable channel into a guaranteed kill setup. The combination of an area-of-effect disable followed by a long single-target lockdown is incredibly difficult to play against.

The partnership hits its stride as soon as Axe gets a Blink Dagger. Together, they can roam the map and secure pickoffs on almost any hero. This forces opponents into a difficult position: grouping up risks a multi-hero Call, but staying separated makes them easy prey for the lockdown chain. The other team needs to either have strong saves to reposition the Gripped ally or get defensive items like Black King Bar much earlier than they'd like, otherwise Axe and Bane can dictate the pace of the entire mid-game.