Slark + Storm Spirit

Why this works

Drafting both Slark and Storm Spirit often creates a lineup that's too greedy with its resources and roles. Both heroes need a good start and lots of farm to hit their timings, competing for safe space. They also want to do the same job: hunt and burst a single target. Storm Spirit pulls a hero in with Electric Vortex, and Slark leashes them with Pounce; using both on one enemy is usually overkill and leaves the rest of the fight uncontrolled. Neither provides the area-of-effect setup or sustained teamfight damage that would enable the other to thrive. They are two solo artists trying to perform a duet.

This leaves the team feeling disjointed. During the mid-game, you have two heroes that want to be active, but they don't coordinate well. A kill attempt with both Storm and Slark often means two mobile heroes are committed to one spot, which can be punished. They also struggle to push objectives after a successful gank. Without strong wave clear or siege potential from these cores, breaking high ground becomes a matter of waiting for the enemy to make a major positioning mistake, which is a risky way to close out a game.