Ancient Apparition + Windranger

Why this works

Trying to burst a single hero with Focus Fire often means the target dies before dropping low enough for Ice Blast's shatter to have an impact. The kill gets secured, but a major strength of Ancient Apparition's ultimate is made redundant. While Cold Feet can help set up a Shackleshot, this laning-stage benefit doesn't scale into the mid-game as well as a strong ultimate combination would. The core of Windranger's damage is physical, so she doesn't gain a huge advantage from the magic resistance reduction of Ice Vortex either.

This pairing often feels like two heroes playing separate games on the same team. Windranger is focused on finding and eliminating a key isolated hero, a goal she can often accomplish on her own. Meanwhile, Ancient Apparition is looking for a big teamfight where he can disable the enemy's healing and control a large area. They don't actively get in each other's way, but their primary objectives and damage types don't overlap enough to create a powerful, unified threat.