Aye, Sain is correct. The mortal/semi-mortal shells of Overlords excisted 1,000 years ago. The time before becoming Overlord can be stretched (as death occured in 1,000 years ago). In regards changing the Echidna's sisters; I am okay with it and presented concepts. Albeit initially Hecate will not recognize the deceased sibling in new form (unless don the old/former appearance in front of her).