Grauphon Berg, also known as Graufon Berg, is a character from the original anime Metallic Rouge. He is one of the nine powerful artificial beings known as the Protoneans, specifically a member of a group called the Immortal Nine. Within the world of the series, these beings are distinguished by their ability to transform into specialized combat forms called gladiators.

Grauphon is aligned with the organization Alter, to which he has pledged absolute loyalty to its leader. In keeping with this devotion, his personality is that of a chivalrous and honorable warrior who favors direct and fair combat. He carries himself with a demeanor reminiscent of a knight and speaks in an archaic or old-fashioned manner, which sets him apart from other characters. His motivations are deeply intertwined with his sense of duty and personal conviction, specifically a profound love and loyalty for a woman named Jill. He views his battles not merely as fights but as duels to the death intended to prove his devotion.

In the story, Grauphon serves as an antagonist, his role primarily defined by his allegiance to his leader and his confrontations with the main cast. He is tasked with battling the protagonists, including the character Eden, who is also one of the Immortal Nine. His key relationships are defined by his loyalty to Jill and his connection to the other Protoneans within Alter, especially his adversarial yet principled relationship with Eden. The character experiences a notable development that concludes in tragedy. Ultimately, he engages in a fatal duel where he self-destructs, an act he undertakes willingly to uphold his convictions. In his final moments, he asks Eden to put a stop to Jill's violence, revealing a deeper concern behind his seemingly absolute obedience.

Regarding his abilities, Grauphon has the power to transform into a massive, gray-colored gladiator. In this form, his signature and notable ability is the manipulation of gravity, which he uses as his primary method of fighting.