"Hercules and the Living Legend" is an episode of Hercules: The Animated Series
Hades realizes from a convention Hercules and Phil are attending that Phil is the key to Hercules' success in training to be a hero, as he teaches him. So Hades visits an old student of his, Achilles (Dom Irrera), who is now a washed-out has-been. Hades offers him his old body and capabilities back, and when Phil is visited by Achilles, he begins to spend more time with him, pushing Hercules to the side until he finally decides he no longer needs a trainer. Hercules tries to prove himself as a hero without Philoctetes by saving Arcadia from a massive fire, but ironically flooded it in the process. However, Hades plan is foiled when Phil realizes he can't leave Hercules on his own and gets back together with him, so Hades returns Achilles to his grey-haired, pot-bellied former state. Memnon, a monster who Hades hired to fight Achilles earlier, takes on Hercules and Phil on the training field, and reveals that Achilles was working for Hades all along. When he knocks Hercules out, Achilles, realizing what it means to be a true hero, steps in and defeats the monster by knocking him out with his massive gut. Achilles then decides to leave to deal with the flood situation in Arcadia.