Or Shadow Desti can be from alternate timeline of "What if Desti never died" from SMG4 What if where after Desti defeated Separoth, Shadow Desit haunt and taunts Desti on how she failed to save Meggy where eventually lead to a alternate version of Sunset Paradise where Desti goes on vacation. In that version of events Aura Boras doesn't get killed by Sir Benedictso so Desti used the Phoenix Egg to revive Meggy instead and eventually disappears.

The revenge of Desti and arrival O_O