Naga Siren + Zeus

Why this works

Setting up a teamfight with Song of the Siren gives Zeus a perfect window to act. While the enemy team is asleep, he can position himself safely to hit multiple heroes when the effect ends. Once Naga Siren cancels the Song, Zeus can instantly unload his entire kit, softening up the whole enemy team with massive magical damage. This follow-up is hard to avoid and doesn't rely on hitting a specific stun, since everyone becomes vulnerable at the same moment. It’s a straightforward way to start a fight with a big advantage.

This combination relies heavily on coordinating around Song of the Siren's cooldown. In many fights, Naga Siren will use her ultimate defensively to save a core or reset a bad engagement, which doesn't give Zeus the same offensive opportunity. Furthermore, Naga is often split-pushing the map while Zeus is posturing with the team. When they do manage to connect for a full setup, it can be decisive, but the enemy team will look to play spread out or force fights while Song is down, limiting how often this ideal scenario happens.