Alchemist + Phoenix

Why this works

Picking these two heroes together is a bet on a specific item timing. Alchemist’s game revolves around accelerating his farm to get items for his team faster than anyone else can. The main idea here is for Alchemist to quickly farm an Aghanim's Scepter for Phoenix. This allows Phoenix to use Supernova to save an ally, which is often the Alchemist himself when he gets caught out. In theory, Phoenix can create a safe zone for his core to play in, turning a gank into a disastrous teamfight for the enemy. It's a loop: Alch provides the gold, and Phoenix provides the save.

In practice, this duo's timings can be awkward. Alchemist wants to stay on the map hitting creeps, while Phoenix is often looking to force fights with his mid-game spell damage. If the enemy team plays aggressively and splits them up, the plan crumbles. Success relies on Phoenix stalling the game long enough for Alchemist to deliver the Scepter. After that, Phoenix can drop his ultimate to control a fight while Alchemist wades in with Chemical Rage and cleans up. The game plan is clear, but it's also predictable and requires both players to be perfectly in sync.