Double Smelling Salts + Heavy Apothecary Combo: nothing special about a strong Vat of Acid. What set this build apart was the salts/apothecary combo, which locked opponents out of matches with 30+ seconds of slow.
Started with a Shiny Quill & Ink that had multicast x3 if I could avoid weapons, and still had a multicast of 2 if I ended up with a weapon. This carried the early game until I picked up Apothecary and two Smelling Salts that allowed Mak to chain slow while charging Apothecary and hasting a Vat of Acid, totally locking opponents out of matches while building a thousand regen and dishing out hundreds of burn+poison, plus doing 3k damage with the Vat. Nothing special about a strong Vat of Acid, but the double Salts/Apothecary combo locking opponents out of matches with 30+ seconds of slow took this build to another level.