Gesicht

Gesicht is a German robot detective, assigned to arrest Pluto for his international crimes against other robots. Gesicht is made out of a special metal called zirconium, which allows him to be near-indestructible and survive extreme electricity. His name means "face" in German.

Story
In both the manga and 1980 series, Gesicht appears in the Greatest Robots arc. Before he can go out to find and arrest Pluto, he is visited by Pluto at his own home. Gesicht attempts to approach Pluto with warrant papers like a regular detective, but the two have no other choice but to fight. Gesicht's unique body indeed helps him withstand the electricity from Pluto's horns, but Pluto splits his horns while Gesicht is holding onto them, tearing him in half.

Abilities
Gesicht's zirconium body is extremely sturdy, and it makes him impervious to gunshots and extreme energy levels. He has super strength, is able to tunnel underground, and can jump several meters in the air at fast speeds. There is a large assortment of laser guns in Gesicht's shoulder and abdominal sections, which he can fire at a target by merely flexing his arms. In the 1960s anime, Gesicht is shown to be able to fly.

Pluto
In a remake created by Naoki Ursawa, Gesicht's role in the World's Greatest Robot story was expanded upon as he is depicted as a humanoid detective. In this version he is working for Europol. His body is made out of an alloy called "Zeronium", and he is capable of firing a devastating blast using the alloy as ammunition. He is also shown with a wife named Helena. Gesicht and many other robots are given humanoid appearances in the manga's plot, where he solves a case of robot and human deaths. The case becomes more puzzling when evidence suggests a robot is responsible for the murders, the first one in eight years.

Note: the following section contains spoilers for the Pluto anime and manga.

Over the course of the case, it is gradually revealed that Gesicht had previously murdered Haas' brother, a robotic child killer, after Gesicht's own adopted child was kidnapped and then destroyed. The trauma and subsequent feelings of hatred were so overwhelming that it left subsequent 'echoes' in Gesicht's memories, such that even after his memories were deleted by Europol (to avoid international scandal), he continued to have nightmares surrounding this event. Brau-1589 similarly hints at this during each of their meetings, teasing at Gesicht's past.

Gesicht eventually recalls his own memories when he is tasked with protecting Haas, filling him with intense feelings of grief, sorrow, and hatred. Despite this, he continues to protect Haas and his family while they remain in witness protection, and does not blame Haas for the actions of his brother. When poignantly asking Haas if the hatred ever leaves, Haas answers by stating that he is not sure if it ever does, but that he now desires to no longer hate Gesicht.

Gesicht returns home to Germany to receive repairs after receiving further damage to his Zeronium shell by extremists by the Anti-Robot Faction. Following preliminary adjustments, he continues his investigations into Pluto and Sahad, wherein he ultimately corners Pluto but chooses to let the latter go after a third party informs him that Dr. Hoffman is in danger and would only be released if Gesicht does not kill Pluto. Gesicht ultimately chooses to abandon further police work as he deals with the conflict of knowing that he has killed a human being, and that his memories had been deleted without his consent.

While purchasing flowers for his wife Helena, Gesicht runs into who he believes to be a flower selling robot named Anton that he has met while in Amsterdam. On close inspection, this turns out to be the body of Ali, an orphaned child robot that had informed Gesicht about Sahad's existence in the first place. Ali, under some sort of control, has a cluster cannon welded to his previously damaged left arm; the latter shoots the unprepared Gesicht, who, still somewhat damaged following his last few battles with the Anti-Robot Faction and Pluto, succumbs to his injuries. His final memories transmit images of Helena and their life together with their robot child.

Gesicht's memory chip is ultimately handed over to Helena as part of his remains. Helena chooses to give this to Dr. Tenma who subsequently installs Gesicht's final memories - what Tenma believed to be hatred - into the unconscious Atom as a bid to wake up the boy.

Trivia

 * In the original manga, Gesicht's name was Gerhart, and in the 1980's anime his name was Zeron.