Would Túrin really return from the dead and kill Morgoth? This prophecy has long roots. From The Book of Lost Tales II: Turambar and the Foalókë Then it changed again in the Sketch of the Mythology or 'earliest Silmarillion'. From The Shaping of Middle-Earth: The Earliest Silmarillion Now we go to The Quenta. From The Shaping of Middle-Earth: The Quenta We have also a Commentary regarding this part. From The Shaping of Middle-Earth: Commentary on the Quenta We have also a reference of Túrin returning in the Annals. From Morgoth’s Ring: The Annals of Aman Yet in the Later Quentas, the Menelmakar, had removed as a sign of Túrin Turambar. From Morgoth’s Ring: Later Quentas Now we come to an interesting change in the philosophy of The Silmarillion, when it changes from being made from an elvish perspective to a mannish one. From Morgoth’s Ring: Myths Transformed And then he have this piece from The Peoples of Middle-Earth: The Problem of Ros So we see the change that have taken place among the place of Túrin in the Second Prophecy of Mandos. First he was made to come back from the dead and slay Morgoth with his black sword, then that conception changed to slaying Ancalagon the Black. The question that arises is can this prophecy be accounted as true? From Morgoth’s Ring: The Valaquenta If Manwë and Varda may know, but have not revealed what would happen in the end of Arda, and Mandos has not declared it, how can The Second Prophecy of Mandos be true then? We have also this little bit. From Morgoth’s Ring: Athrabeth Finrod Ah Andreth, Note 7 So, it seems clear that the Prophecy of Mandos, (at least the part awarded to Andreth), is just a tale made by her, but if the Eldar had no knowledge of the end, how can it be proven to be true. We may choose to believe that is true, but we can’t prove that it is so. If you want to believe it, you would need estel.