Lich + Queen of Pain

Why this works

Pairing a mobile assassin with a more stationary, defensive support can feel awkward. Queen of Pain wants to Blink onto a target and secure a fast solo kill. While Lich can offer a slow with Frost Blast to help her connect, his most impactful spells require a different kind of fight. Frost Shield is best used protecting an ally under fire, and Chain Frost needs enemies to be grouped up. A Queen of Pain hunting for an isolated hero on the edge of the fight doesn't naturally create the brawls where Lich gets the most value from his kit.

The laning stage can be decent, as any slow helps Queen of Pain land her damage. As the game progresses, however, their objectives diverge. She will want to use her mobility to find pickoffs across the map, playing an aggressive, independent game. Lich is much slower and prefers to group with his team to set up for larger engagements. This often means QoP has to limit her own aggressive potential to play around Lich's spells, or she blinks in so far ahead that he can't offer any backup. They can end up playing two separate games on the same map.