mythologize
US /maɪˈθɑː.lə.dʒaɪz/
UK /maɪˈθɑː.lə.dʒaɪz/

1.
to create a myth about something or someone; to treat something or someone as a myth or legend
:
•
The film tends to mythologize the historical figure, often overlooking his flaws.
•
Over time, the simple story was mythologized into a grand epic.