Board Thread:Spoilers!/@comment-2153169-20151015134011/@comment-24674051-20151109222114

Interesting thoughts. But I don't recall any names on the sword as of last night. and the fact that the sword in the picture has BOTH names on it give rise to the theory that Hook did indeed kill Merlin (whether accidentally or otherwise is yet to be seen) with the sword part of Excalibur back in Camelot. and I would imagine that, since it is implied that the same spell that tethered the Dark one to the Dagger was used, then Killing Merlin with Excalibur transfers the tethering to the one that was wielding Excalibur at the time.

And having Killian tethered with Merlin's magic, while Emma is tethered with Nimue's magic, is a great parallel, given the relationship between Killian and Emma.