Alchemist + Pugna

Why this works

Using Decrepify on an enemy to set up a kill often backfires for this pair. While Pugna can follow up with high magical damage, the ghost form completely blocks the physical damage from Alchemist's Unstable Concoction and all of his right-clicks. This can leave Alchemist helpless in a fight, waiting for the effect to end while a key target gets away. Even Pugna’s efforts to save Alchemist can be awkward; using Decrepify on him prevents him from attacking, and using Life Drain to heal him during Chemical Rage is often less impactful due to the massive regeneration Alchemist already has.

The strategic pacing of these two heroes can also be out of sync. Pugna is often looking to group up and pressure objectives early with Nether Blast, whereas Alchemist typically wants to isolate himself and farm for as long as possible to accelerate his item progression. When their timings don't align, they effectively play two separate games on the same map. If they can coordinate, however, Pugna's saves can be valuable for keeping a farmed Alchemist alive, and their combined pushing power can be strong. Success really depends on whether their different game plans happen to intersect.