I don't want to write a huge review here so I'll try to keep it short. This short story or novella starts up promising with a very interesting premise and atmosphere but soon reveals its failures.
The first is the pacing, which is rather inexcusable from an author of Moorcock's calibre. The pace of the story was awful for such a short story. So much infodump and history and background and so little action in-between.
Second is the main character who is rather unlikable but not in an anti-hero kind of way but rather because he's just too much, a pulp cliched exageration of juvenile fantastical gun-slinger/knight/something. Towards the end I didn't really care what happened to him, really, I think I wanted him dead while knowing that he will come on top anyway.
I have read a lot of Moorcock and I don't doubt his ability as a writter as I have loved his stories but this one was a bad one for my taste.