He appears as a gigantic metallic robot .
Built by Komui with the intention of it lightening the workload of
the Science Division, it was fully capable of performing surgery and repair work to Anti-Akuma Weaponry. Komui, though, programmed it to share his intelligence level and personality, resulting in it apparently sharing his love of coffee. It drank Komui's coffee and went insane, first attempting to make Lenalee Lee more masculine.
When Komui told the Komlin that Allen's Innocence was damaged, the robot made Allen its top priority and trapped it in the surgery room built into its hull. Lenalee then regained consciousness and kicked the Komlin (as well as her brother when he tried to defend it), making it explode.
It was later revealed by way of an after chapter special that Reever Wenhamm and the other members of the Science Division dismantled the Komlin II, and afterwards the robot was smashed in a hydraulic press, though in the anime, Komlin II was being kept in storage, which allowed Komui to steal and upgrade it in his attempts to destroy Russell when he thought Russell was dating his sister.
- Komui's perception of Komlin II changes slightly between the Japanese and English versions: In the original, Komui proudly refers to it as his "scientific work of art", when the dubbed version has Komui refer to Komlin II as his "son" or "baby".