User blog comment:ImperiexSeed/Supernatural Mysteries/@comment-3481504-20120502152425/@comment-3045936-20120502155212

The the lore of their history. As the Shtringa isn't killable except when feeding, the ppl at that time thought that nothing could kill it. Similar principle with deities, as they normally are only killable with their respect weakness, being with immense power can also kill them.