I prefer
Ottavia. The Double T sounds a little bit softer than the C. It sounds a little bit more feminine and girly to me. But I do like
Octavius and
Octavian fine enough. Robust.
Please rate my "Names I would Use" list & "Backup Favorites" list. Feel free to rate some of my other lists too if you have the time.
https://www.behindthename.com/pnl/223226/138473