Underlord + Axe

Why this works

Picking these two heroes together is often a plan to create an unbreakable frontline. Axe wants to get a good Berserker's Call, but that can be a high-risk play. Underlord makes his job much safer. Atrophy Aura reduces the attack damage of enemies caught in the taunt, making Axe significantly harder to bring down. A well-placed Pit of Malice can also root targets, setting up an easy initiation for Axe. Once he jumps in, Underlord can blanket the area with Firestorm for heavy follow-up damage.

This pairing looks to control the map as a group in the mid-game, forcing fights around towers and Roshan. Underlord can use Fiend's Gate to move the team, setting up ganks where Axe can suddenly appear and initiate. The reason this isn't always a winning plan is that it can be countered by good positioning and disengage. Teams with Force Staffs or mobile ranged heroes can kite Axe, preventing him from ever getting a clean Call. The duo's success often relies on the enemy draft lacking the tools to simply walk away from them.