Keeper of the Light + Legion Commander

Why this works

Getting caught by a Duel is bad enough, but it's worse when Keeper of the Light is nearby. His ability to restore Legion Commander's mana is the core of this partnership. It lets her spam Overwhelming Odds to clear waves, accelerating her farm for key items. She can also use Press the Attack more freely for sustain, keeping her ready to fight. When Legion finally commits to a Duel, Keeper of the Light can blast the target with Illuminate from a safe distance to help secure the kill. Blinding Light can also shove other heroes out of the fight, isolating the Duel target.

This creates a relentless mid-game pace. Legion Commander isn't forced to return to base for resources; she can stay on the map, farming enemy territory and constantly looking for pickoffs. Her team can play around this pressure, knowing she's always topped up. For the enemy, splitting up means getting caught by a full-mana Legion, while grouping up invites a devastating Illuminate. The main counterplay is to jump and kill Keeper of the Light first, but his backline positioning makes that difficult before the Duel is already over.