Wraith King + Viper

Why this works

Catching a single target out of position is this duo's specialty. Viper's constant slows from Poison Attack and Viper Strike make it incredibly difficult for an enemy to get away, effectively pinning them in place. This gives Wraith King, a hero who can struggle with sticking to mobile targets, a free pass to walk up, land Wraithfire Blast, and start hitting. The target is forced to eat heavy physical damage from Wraith King and stacking magic damage from Viper, a combination that is very difficult to itemize against.

The strategy usually revolves around an aggressive mid-game timing. Viper creates pressure and controls the map, giving Wraith King the space he needs to secure his first major items. Once together, they look for pickoffs to convert into objectives. The primary counter-play is to avoid getting caught in the first place, using mobility items or team saves to create separation. If the enemy team can't split this pair up or kite them effectively, they'll find themselves losing heroes before teamfights can even begin.