Although urged to evacuate, he is uncertain, as his plans would be set back considerably if he had to leave. While developing new weapons, the Syndicate are attacked by the Invaders Annette and Schwarz Metzelei. The Doctor survives, but is clearly not pleased. The Doctor laughs at her incompetence, just as the grenades fall on top of the Mother Computer and destroy it. Rumi then counterattacks by throwing grenades, but it appears to be clumsily thrown.

When confronted by the clumsy Rumi, he tries to kill her with the machine's lasers, but she dodges all of them. In 'Amadeus' Revenge' Extra Ops, he tests out a new Type Оі Mother Computer and is delighted with the results. Prior to the creation of White Baby, he created First Baby, but locked her away after she became extremely unstable. Not having any children of his own, he created various AIs to mimic them, as shown with White Baby and Iron Fortress as both are AI appearing as children, and has grown attached to them as a father figure. Just like in Metal Slug 4, he is affiliated with the Rebel Army, working with them in some occasions.

The Doctor appears several times in Metal Slug Attack. Whether he survived the destruction of the Mainframe base or not is unknown. After defeating him, the base begins to collapse while he is still stuck inside the last machine. He controls the Amadeus Mother Computer, a three part contraption. As the head of the Amadeus Syndicate, the Doctor helps Morden to obtain new weaponry and also creating his own army.

Metal slug tv tropes