If you want a bold name that is still subtly connected to Ravenna, a quick search on the nameberry page and wiki article shows a lot of cool literary and historical possibilities like Dante, Cato, Lionel, Wilde, Apollinaris/Apollo, and Byron for boys; and Clairvaux, Beatrice, Apollina, and Constance for girls.
(I looooove the idea of Byron. It’s along the same lines as Tennyson which was my favorite suggestion from the article. And I think Byron is a great a style match for Ravenna—it’s bold and unexpected and dignified but not unheard of. And it also brings to mind the line in Byron’s “She Walks in Beauty” about the “nameless grace that waves in every raven tress”, another possible but very subtle connection to Ravenna)
Other thoughts:
Damien
Caspian
Jasper
Valentine (could also use for a girl imo)
Petra
Moira
Althea
Cecily
Leonor