Arc Warden + Vengeful Spirit

Why this works

Vengeance Aura on a Tempest Double sounds like it should be powerful, but the two heroes often have conflicting goals. Arc Warden excels at splitting the map and farming safely with his clone, playing far from his team. For the aura to have an impact, Vengeful Spirit needs to be nearby, which pulls her away from the active parts of the map where she wants to be. While a Nether Swap can be a decent save for the real Arc Warden if he gets caught, it's a standard tool she provides for any carry and doesn't create a unique advantage here.

The result is a pairing that only really clicks during specific moments. For most of the game, Arc Warden will be pushing out a lane by himself while Vengeful Spirit tries to create pressure with the other heroes. They come together when sieging high ground, where the clone can get full value from Magnetic Field and Vengeful Spirit's buffs to attack towers. Outside of those set-piece pushes, however, they mostly play their own separate games. The synergy isn't disruptive, but it’s rarely strong enough to be the main reason a fight or game is won.