Aredhel

"Though it was made of the same ore..." [chuckles] You know, I love how he says it's not gonna enter this tale, but then here's the information about it.

Uh, "It was made of the same ore by the same smith, and that smith was Eöl the Dark Elf, who took Aredhel, Turgon's sister, to wife.

He gave Anglachel to Thingol as fee, which he begrudged, for leave to dwell in Nan Elmoth.

But the other swo- sword, Ang- Anguirel, its mate, he kept until it was stolen from him by Maeglin his son." Right, so it doesn't really come into the tale, but he tells us about it.