When Shantae arrives on Frostbite Island, she spots the Techno Baron in conversation regarding the completion of a Targeting Device for one of the Ammo Baron's cannons. Not recognizing Shantae, he sends her to Propeller Town to pick up the device and deliver it to the Ammo Baron, which she does with extreme reluctance. As it turns out, Bolo was hired to construct the device, which (unsurprisingly) results in the cannon misfiring and blasting the Techno Baron right where he stands. This coincidentally also reveals the entrance to the Abandoned Factory, the last Den of Evil in the game.
Techno Baron returns in Shantae: Half-Genie Hero. When Shantae learns that maidens are being kidnapped and shipped off to Mermaid Falls, she initially assumes that the mermaids on that island are responsible. However, when she goes to investigate, she discovers a factory where the captured maidens are being turned into "fake mermaids" by having their bottom halves eaten by fish. After traveling through the factory, Shantae finds out that the Techno Baron has kidnapped the mermaids' queen, Giga Mermaid, whom she frees after a tense battle. After Giga Mermaid is rescued, the Techno Baron admits that he was behind the "fake mermaid" scheme, as he was unable to capture enough "real" mermaids for his latest scheme.