Probably a modern English elaboration built from Deon or Dion with a creative -sha ending.
Deonsha is probably a modern English elaboration built from Deon or Dion with a creative -sha ending. That ending gives the name a smoother, more feminine cadence and places it firmly in the modern habit of extending short roots into more ornate forms.
The name feels current, expressive, and rhythm-driven. It has the kind of sound that is more important than long etymological continuity, yet it still preserves the strong opening of Deon, which keeps it grounded. Deonsha is distinctive in the best modern sense: familiar enough to pronounce easily, but shaped enough to feel personal and original.