Ancient Apparition + Void Spirit

Why this works

Landing Aether Remnant creates a reliable setup for Ancient Apparition's Cold Feet, guaranteeing a stun. This gives the pair a decent way to lock down a single hero for a kill, especially during the laning stage or early rotations. Void Spirit can pull a target in, letting Apparition layer on his spells from a safe distance. The magic resistance reduction from Ice Vortex also gives a small boost to Void Spirit's spell damage when he commits with Dissimilate. The whole sequence relies on that initial Remnant, though; if it misses, the heroes don't offer each other much direct support.

In practice, their overall game plans don't always line up perfectly. Void Spirit wants to be highly mobile, zipping in and out of fights with Astral Step to find and burst isolated targets. Ancient Apparition prefers a more static, drawn-out teamfight where his spells can control space and his ultimate can wear the enemy down. This can lead to situations where Void Spirit makes a play on his own and is already gone by the time Apparition is in position to follow up. While Ice Blast can always secure a kill from across the map, the core moment-to-moment teamwork can feel a bit disconnected.