Brand new feat for Naga Sadow?
"On Yavin 4, Freedon Nadd learned all he could from the spirit of Naga Sadow."
"(...)and it is thought that Nadd extinguished Sadow's spirit."
In 3756 BBY, Naga Sadow(possessing Eison Gynt) is struck down by Barel Ovair.
Yet, during one period of intense Force activity on the moon in 3638 BBY, Sadow's spirit manifested as a ghost in the jungles of Yavin 4.
It is thought that Naga Sadow's spirit had been destroyed by Nadd(which makes sense) because he didn't appear when Exar Kun became a Dark Lord.
He is struck down a second time by Barel Ovair.
And even after dying a second death, he still could manifest himself as spirit in 3638 BBY
Doesn't mean that Naga Sadow(as spirit) was able to escape the Chaos realm through his sheer will twice?