Phantom Assassin + Shadow Demon

Why this works

Trying to set up a kill for Phantom Assassin often feels clumsy with a Shadow Demon on the team. Disruption is the main issue; it works best by holding an enemy in place for a delayed area-of-effect spell. Phantom Assassin has no such ability. She has to wait for the target to reappear before she can use Phantom Strike, giving the enemy a window to use an escape or defensive item. The illusions created from an enemy are also a poor fit for her goals, as they are easily cleared and serve as a distraction more than a real threat.

This disconnect starts in the lane, where the pair has very little kill threat and can struggle to secure farm for Phantom Assassin. Later in the game, they operate on different timers and from different positions. Shadow Demon wants to poke and control from the backline, but PA needs an ally who can enable her to jump aggressively or create chaos up front. Using a defensive Disruption on Phantom Assassin can save her, but it also removes your main source of damage from the fight for its duration, often wasting her momentum or BKB timing.