When the Prince is transformed, the Dark Prince takes his place in physical form. The Dark Prince's body resembles a charred form of Prince's own, surrounded by smoke that emanates from his body, engraved with elaborate flowing designs that represent the sentience of the Sands of Time. His eyes become glowing golden due to the Sands. His hair stands upright, mirroring smoke and burning cinders. His arms and back covered with black scaly thorns. He embodies every negative aspect of the Prince, his rage and pride giving him physical form and energy to feed off of. As the Sands drain from his body, the eyes and flowing designs on the Dark Prince's body gradually lose glow and color, becoming yellow at first, than red, and ultimately black when the Dark Prince is near death due to severe loss of the Sands
The Dark Prince embodies the dark and negative aspects of the Prince, outwardly making him the opposite of the Prince's positive personality traits. While the Prince cares for others and would go out of his way to save them, the Dark Prince shows little compassion for anyone and will ignore their suffering. He told the Prince that the only way to save them is in killing the Vizier.
The Dark Prince possesses a somewhat morbid personality, and seems to relish in killing, going so far as asking the Prince if the brutal slaughter of a colony of Dark Reptus felt good, upon his initial transformation. He also possesses a dry and sarcastic sense of humor, often taunting Prince during or after combat, accompanied by sarcastic remarks on Prince's fighting skills, as well as genuine congratulations.
The Dark Prince disliked Farah and told the Prince that she would be a hindrance to their mission and they were better off without her. The Dark Prince's dislike for Farah was so great that he was sickened by the mere conversation the Prince had with her. The Prince believed that his alter-ego was jealous of Farah because she received more attention than him. Despite this, the Dark Prince gave a mysterious comment about him and the Prince wanting very different things from Farah, hinting he is possibly sexually attracted to her.
Despite viewing Vizier as an enemy to be killed, the Dark Prince considered his ascension to power as something wonderful. Being a manipulator himself, the Dark Prince was able to figure out that the Vizier was trying to provoke the Prince into making a mistake by avoiding and told his counterpart that not every battle is being fought physically and there are battles waged and fought mentally. He later demonstrates this by dragging the Prince into his subconsciousness, attempting to destroy the Prince on his own field.
Throughout the journey both the Prince and the Dark Prince would engage in conversation and explain how they would solve their problems, with the Dark Prince's being more violent in nature while the Prince would try to reason against this. Over time however the Dark Prince and the Prince's interactions with each other would decline as the Dark Prince became more condescending and insulting to his host, eventually resulting in the Prince finally snapping back at his darker alter ego and stating his utter contempt for his darker side. It isn't until they find the Prince's dead father and the Prince finally accepting responsibility for his actions does the Dark Prince finally stop talking, as well as trying to take control of the Prince's body. However after the Vizar is killed the Dark Prince returns and drags the Prince into his mind to finally take control over him, it's this final battle that the Dark Prince shows he actually relies on the Prince to stay in existence, begging him not to leave him as the Prince ignores and walks away from the mental throne room back to the real world.