Death Prophet + Venomancer

Why this works

Stacking damage-over-time effects rarely leads to a clean kill. Both Death Prophet and Venomancer apply immense pressure, but neither offers the hard stun needed to hold an enemy down. A target slowed by Venomous Gale can still teleport away, and a silenced hero can still use items like Force Staff to escape Exorcism's ghosts. This lack of lockdown means enemies frequently survive with a sliver of health. Furthermore, both heroes deal primarily magical damage, allowing opponents to counter the entire strategy by building a single Pipe of Insight or grouping under a Guardian Greaves.

This forces a specific game plan that is very easy to disrupt. Death Prophet and Venomancer both want to group in the mid-game and choke out the enemy with sustained pressure on their towers. The problem is that without a strong initiator, this push is fragile. The enemy team can simply back off while Exorcism is active, then re-engage the moment it ends. They are not forced to fight into the combined ultimates. This leaves your team vulnerable to being picked off or collapsed on by heroes who can punish the lack of instant disables.