Board Thread:General Discussion/@comment-6192846-20140612134000/@comment-6192846-20140812041335

DemonDamian wrote: Super late answer, I know, but the words I heard referring to the "Demon Sword" were most certainly "魔剣" (Maken), so, unless Mothy decides to use unconventional kanji (very possible, though), it doesn't seem like the song will be using 刀 in that part. Thanks for the clarification. My dictionary says this literally means "cursed sword(s)" and individual kanji means demon/evil influence and sword/blade/saber.

The Twin Swords use 双剣 so they share the same last kanji. Based on that, I'm feeling confident that it is referring to the twin swords but we'll see.