Necrophos + Troll Warlord

Why this works

Trying to save a hero during Battle Trance is usually impossible, but Necrophos's kit doesn't care. His Death Pulse heals in an area, so it keeps Troll Warlord topped up even while he's uncontrollable and diving deep into the enemy team. Meanwhile, Heartstopper Aura is constantly softening up every enemy near Troll, making his right-clicks hit that much harder and bringing targets into kill range faster. Necrophos provides all the sustain Troll needs without ever having to click on him, turning the ultimate from a risky commitment into a sustained teamfight wipe.

This dynamic creates a nightmare for the opposing team. They can't ignore Troll Warlord because he's tearing through their heroes, but focusing him is difficult when constant area-of-effect healing keeps him fighting. If they try to bypass Troll to get to Necrophos, they have to run through the very frontline they were trying to avoid. Once a key enemy gets low, Reaper's Scythe finishes the job, securing the kill and the advantage. The enemy is forced into a no-win choice between bad targets, which usually ends with their team falling apart.