This looks wildly uneven, sorry. You have a storied name from Greek mythology paired with a modern English noun / virtue name, and it's visually jarring. (I'm also not digging the dual long-E endings.)
If we were to take the Latin form of Serenity, and have the combo Ariadne Serena (because of the two names, I think Ariadne is the one that should be kept), I this this is both visually and aurally more appealing.
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Please rate my personal name lists:
www.behindthename.com/pnl/69381www.behindthename.com/pnl/69381/117507www.behindthename.com/pnl/69381/109399hwww.behindthename.com/pnl/69381/132018http://greens-end.myminicity.com/env