User blog comment:Retro7/Fairy Flush Reviews: Where The Dragon's Spirit Slumber/@comment-5341942-20120923080756/@comment-4829046-20120923152008

There are a few theories for Lucy's arm being gone

1.Lost in the battle

2.Sacrificed it to save the remaining FT members

3.Had to lose it to the eclipse plan

4.Zeref destroyed it when she betrayed her