Final answer:
Achilles is an archetypal hero in the Iliad due to his semi-divine origin, supernatural strengths, and the prophecy surrounding his fate. These elements are evidenced by his invincibility save for his Achilles heel and his celebrated martial skills, represented in both the narrative and ancient Greek artistic depictions.
Step-by-step explanation:
Achilles is an archetypal hero in the Iliad for several reasons that align with the traditional attributes of a classic hero. First, his origin story is marked by a semi-divine intervention; as a child, his mother dipped him in the river Styx, which was supposed to make him invincible except for his heel, which she held him by. This vulnerability contributes to his status as a tragically fated hero. Second, Achilles' extraordinary physical prowess is highlighted throughout the epic, including his special armor forged by Hephaestus, the god of the forge, indicative of the supernatural aids often bestowed upon heroes in mythology.
Achilles' prowess and fate are also symbolically represented in artistic works of the time, such as an amphora that captures a moment of tension between Achilles and Ajax during the Trojan War. In this depiction, Achilles is winning a dice game against Ajax, foretelling his eventual victory in battle and his legacy as the greater warrior. Moreover, the details such as Achilles' relaxed posture and grip on the spears, contrasted with Ajax's tenseness, underscore his natural heroism and leadership. Such representations echo the narrative of the Iliad, where Achilles is consistently portrayed as a mightier figure.