Antonyms for the phrase "assumed the role of" could include "relinquished," meaning to give up or surrender a role, as well as "rejected" or "refused," meaning to decline or turn down an offered role. "Abdicated" is another antonym, suggesting the deliberate abandonment of a position of authority or responsibility. Conversely, "delegated" might be seen as an antonym that suggests handing over a role or responsibility to someone else. "Disavowed" or "disclaimed" also represent antonyms, denoting a denial of a role or disassociation from it. Overall, these antonyms highlight the various ways in which individuals can choose to engage or disengage with specific roles or responsibilities.