: Perhaps the Deceiver's first goal is to destroy Shiver
: and Soulblighter, even if his ultimate goal is for the
: Dark to triumph (albeit, with him in charge). Letting
: the dam break would kill Shiver, but ensure
: Soulblighter's victory. He has to save her for now in
: order to ensure the destruction of both Fallen Lords.
The Deceiver wants nothing to do with ruling the Dark. He was fond of Cath Bruig and favors a stable civilization. It seems to be clear that he is paving the way for a rebirth of the Empire.
The Deceiver is not evil in terms of the desire to destroy the world. He had to be a Fallen Lord, there was no choice. But, he eventually got out of it and all of his more recent actions seem to point towards a desire by Myrdred to stick around and be present as the Empire rebuilds.
The last thing he wants is an entire thousand year period of Dark rule.
Chris