To find the boss, you need to Teleport to the Debender map.
Reward for killing the boss:

Darkangel Sword
Darkangel Magic Sword
Darkangel Claws
Darkangel Scepter
Darkangel Bow
Book of Darkangel
Darkangel Staff
Darkangel Stick
Darkangel Shield


Sets:
Darkangel Knight Helm  
Darkangel Wizard Helm 
Darkangel Elf Helm (A)
Darkangel Summoner Helm
Darkangel Lord Helm   
Darkangel Fighter Helm
Darkangel Elf Helm (B)

Darkangel Knight Armor   
Darkangel Wizard Armor   
Darkangel Elf Armor (A)  
Darkangel Summoner Armor 
Darkangel Magic Armor (A)
Darkangel Lord Armor     
Darkangel Fighter Armor  
Darkangel Elf Armor (B)  
Darkangel Magic Armor (B)

Darkangel Knight Pants   
Darkangel Wizard Pants   
Darkangel Elf Pants (A)  
Darkangel Summoner Pants 
Darkangel Magic Pants (A)
Darkangel Lord Pants     
Darkangel Fighter Pants  
Darkangel Elf Pants (B)  
Darkangel Magic Pants (B)

Darkangel Knight Gloves   
Darkangel Wizard Gloves   
Darkangel Elf Gloves (A)  
Darkangel Summoner Gloves 
Darkangel Magic Gloves (A)
Darkangel Lord Gloves     
Darkangel Elf Gloves (B)
Darkangel Elf Gloves (B) 

Darkangel Knight Boots   
Darkangel Wizard Boots   
Darkangel Elf Boots (A)  
Darkangel Summoner Boots 
Darkangel Magic Boots (A)
Darkangel Lord Boots     
Darkangel Fighter Boots  
Darkangel Elf Boots   
Darkangel Magic Boots (B)