Currently one handed mythical weapons are from the mythical epic quests that players can do.  These quests involve killing varying mobs and usually end with a hard to kill mob in Veeshan's Peak a rank 4 zone in Rise of Kunark. 

Below you will find the current list of 1hw in the item database.

• \aITEM -1598683725 1405079690:Betrayal's Song\/a (Image)
• \aITEM -1270934779 -1248783613:Doomcoil's Deactivated Control Baton\/a (Image)
• \aITEM -944632938 -63632483:Double Eye Poker\/a (Image)
• \aITEM 1586908060 1407254121:Empowered Talon of Milyex\/a (Image)
• \aITEM -135033677 -1385136790:Jade Reaver\/a (Image)
• \aITEM -1478755540 1371701413:Lamentation of the Intrepid\/a (Image)
• \aITEM 1051355391 1348416678:Love's Lament\/a (Image)
• \aITEM -1307469115 831613028:Prismatic Scepter of the Scale\/a (Image)
• \aITEM 542102284 1453819796:Quickened Rod of the Watch\/a (Image)
• \aITEM -719838392 1837423902 -931987979:Ryjesium Forged Knuckles\/a (Image)
• \aITEM 2105874081 -268102059:Segmented Serrator\/a (Image)