Board Thread:Lore Discussion/@comment-10993011-20130618024431/@comment-8248675-20130802182121

Actually, I don't think having another heir would help not to break the amulet, if you remember correctly they were going to relight the dragonfires with it, to keep Dagon from comming into Tamriel. However, by the time that they got on their way to Temple of One, Dagon already walked out of the Oblivion gate. They had no choice after that, the relighting of Dragonfires would only work if Mehrun Dagon was still inside Oblivion. Martin sort of had a last minute idea either on the way to Temple of One, or inside it. I am not even sure he knew it would work, but lucky for Tamriel, his sacrafice was not in vane and an Avatar of Akatosh had banished Mehrun Dagon back into Oblivion. I don't think having another heir would had prevented the need to break the amulet of kings at that point.