The Wings of Solemn Death are obtained by killing Amadeus De Roha found in the 2nd level of Rahkon.
The Wings normally drop when he is killed. The Wings are useful to anyone using a melee weapon such as a Sword, Mace, Axe, Zen or Katar. Since the Wings of Solemn Death are a blue named item, it cannot be traded in-game. It can only be traded through the exchange market. It is highly recommended any party's killing the Amadeus De Roha to set the party's distribution to "Free" and have any melee weapon users obtain the item.