How are the both book 11 of the Odyssey and "Ozymandias" related?
The overriding theme of Shelley's "Ozymandias" is the transience of all earthly things. Ozymandias, an Egyptian pharaoh, thought he could achieve immortality by his achievements in this life. Yet his statue lies crumbling in the desert, representing a warning to those foolish enough to think that they can withstand the ravages of time.
A similar theme emerges in book 11 of the Odyssey. Odysseus, on the instructions of Circe, visits the Land of the Dead in order to consult the blind prophet, Tiresias. In Hades, Odysseus is confronted by his own mortality as he meets with the shades of his former comrades-in-arms such as Agamemnon and Achilles.
It is his meeting with the latter that links up with the theme of "Ozymandias." Odysseus always believed that Achilles, like all other great heroes, had achieved immortality through his noble deeds on earth. So Odysseus is somewhat taken aback when Achilles proclaims that he'd rather be a farmer's slave on earth than king of the dead. Evidently, immortality in the Odyssey proves no more desirable than in "Ozymandias."