When you have unlocked Act 5 you will be able to access the Deathless Blade Master's Collector's quest where you must fight your way through Slot Canyon to the ancient temple in the Collector's lair and defeat The Collector to win exclusive weapons for each character. In order to fight The Collector you must place your equipped weapon up as a prize which you will lose if you are defeated. The six weapons you can win from The Collector are as follows.
Blade of Eradoom:
Level 5, Isa
The Subtle Knight:
Level 6, Isa
Spear of Teth:
Level 8, Isa
Lost Axe of Galath:
Level 4, Siris
Orci: Level 7, Siris
The Dragoor Blade:
Level 9, Siris