At the end of Ar Tonelico II - Melody of Metafalica when Luca and Cloche are singing EXEC_with.METHOD_METAFALICA/. Frelia is warning Infel that if Luca and Cloche are successful Infel will disappear because of what will happen to the Infel Pira, all the while Infel is saying she knows she's going to disappear because she designed Infel Pira.
But i am wondering, would Infel had disappeared when she and Nenesha tried to create Metafalica 400 year ago and succeeded? does this mean Metafalica was doomed to fail back then because it would require someone to sacrifice their life?