Monkey King + Phoenix

Why this works

Placing two massive teamfight ultimates together feels like a good plan, but Wukong's Command and Supernova often work against each other. Monkey King creates an arena and needs enemies to stay inside it so he can build up damage with his staff. When Phoenix uses Supernova, however, opponents are forced to either attack the egg or flee. Fleeing enemies will naturally run out of Monkey King’s circle, leaving him hitting air. Phoenix also doesn't provide the kind of lockdown that guarantees MK can get his Jingu Mastery stacks on a key target before they can react.

Across the game, this duo can feel disconnected. Early laning doesn't offer much kill potential, as their abilities don't set each other up well. In mid-game fights, they have to coordinate perfectly, which is difficult. If Monkey King jumps in and Phoenix follows with Supernova, the fight's focus splits in a way that can be unhelpful for both heroes. The enemy team can often disengage from one hero's ultimate to deal with the other's. This forces the Monkey King and Phoenix to play almost sequentially, rather than together, which reduces their overall impact.