"By your post, the DO should be freed instead [Curie asks:instead of what? Be balefired and killed?], so that he/she/it may rejoin the Creator and become a single entity again".

You are right, it is my line of thinking. What I like to disscus, is an alternative:

-Creator and DO are on the same level, e.g. they are in balance, each having equal power, being the Creator and the Destroyer. They were established by the Primal Entity from Itself. Current status of the Primal Entity, even its name, are unknown to us. Probably It does not exist any more. Creator founded Universe and exists somewhere, we do not know where. DO fights him directly as Shaidar Haran and using his champion - Moridin. Creator defends himself and his creation using his champion - Dragon. It is a very manicheian approach.

-Creator was/is the Primal Entity, the Overgod. He created Universe from himself by dissipating part of himself into his creation. He is the Pattern and the Wheel. The rest of the Creator, not spent for creation, is Lord of the Dark, aka DO. He/She/It wants disassemble creation and, in a way, rejoin the Creator and become the Primal Entity again. To do it, he needs approval from Creator's champion - Dragon. Achieving this, Primal Entity can recreate Universe in the new, different shape. If Dragon will be able to unravel webs maintainig the bore, DO will be imprisoned. He will try to destroy Universe next time with new position of the Wheel.

I rather vote for a second explanation. This is my jibber jabber for adults.