"Take this; my final gift to you!"
In order to redeem himself he tries to destroy Zemus himself even if it comes at the price of his own life. Golbez appears to care deeply for his younger brother Cecil, understanding his resentment towards him and smiling (through an image of his child self) after Cecil calls him "brother". In The After Years, Golbez's first thought when he realized the Blue Planet was in danger was his brother's safety. Without revealing his true identity, Golbez helped Cecil's friends, always keeping a certain distance from them. He was the first to enter Baron Castle and, upon finding Cecil unconscious after being broken free from his possession, Golbez rushed by his side. He would also willingly sacrifice himself for his brother when his dark side, the Dark Knight, attacked him. When fighting the Archfiends in the True Moon's Subterrane, Golbez shows some measure of compassion to his former allies, despite their misdeeds in the past.
Dissidia Final Fantasy somewhat merges these two aspects of Golbez's personality - the caring brother and the cruel manipulator. Golbez appears to Cecil numerous times to offer him assistance, and also appears to help the other Warriors of Cosmos. He does so at his own risk, as Exdeath arrives to attack him when he is discovered of treachery. However, he also harbors his own schemes separate from the other villains, and manipulates the heroes, though he usually does so with the intent to help them. This is most notable with Firion, where it is implied that Golbez created the rose that inspired Firion's dream and placed it for him to find for this exact purpose. Golbez is the only villain to speak with Cosmos, discussing her plans for the heroes. In this, he is something of a double agent. Golbez also has no qualms about attacking the heroes when called upon, including Cecil, though he does so with the ultimate goal of assisting them.
Theodor was born to Kluya and Cecilia. While growing up, he always wondered why his father was fascinated by the moon and was unaware of his father's origins as a Lunarian. His father would not tell him until he had mastered the arts of magic. Theodor boasted that he can cast magic, but when his father asked if he has even mastered the Cure spell, he admitted he cannot. When Theodor returned home afterward, he saw his mother collapsed on the floor. She told him she was alright, and that she is just tired from carrying her next child. Excited about having a brother, Theodor went to bed.
Later, Kluya was attacked by the very magic he had taught to humans. When Kluya wondered if it was right to teach the people of Earth magic, Theodor assured his father it was, comforting his father in his final moments. As Kluya passed on, Theodor tried to cast Cure on him, but was unable to. The villagers took care of Theodor and Cecilia afterward, and when Cecilia finally gave birth, she died in labor. Shortly after their mother's death, the children are seen alone in their house. While staring at his brother, Theodor heard a voice telling him the baby was the one responsible for taking his mother and father away from him, and that he was worthless for letting it happen. The voice told him he was "an insect born from a dragon's corpse", and declared his new name was Golbez. Controlled by the voice and filled with hatred towards his brother, Golbez left him just outside of Baron. The infant grew to become Golbez's brother Cecil Harvey.
In reality, the voice was Zemus. Taunted by Zemus's voice and ashamed of his actions, Golbez fled civilization. Eventually, combined with Golbez's Lunarian blood and his hatred of his younger brother, Zemus was able to influence his mind and take control of him. Golbez subsequently lost many of his memories and began to gather the Crystals to summon the Giant of Babil. The Giant would then depopulate the planet so that the Lunarians, presumably under Zemus's control or command, could live there rather than stay in stasis inside the moon.