There ARE some good ideas here. The overall arc of the plot is excellent and there are some really nice bits (in the second scenario in particular).
Unfortunately the adventure is plagued with ... look. In the gamebooks you are playing a single specific character, Lone Wolf. If you die and play the game again you are still playing Lone Wolf. You aren't putting in the effort to create a new and dynamic personality from scratch. There's also no one else present to be frustrated, or that will be unable to proceed because of the loss of your character's skills.
In a tabletop adventure module players have more invested in their character than two die rolls, five picks off a list and half an hour of reading. The loss of one character will affect both the group's survivability and their experience.
Terror of the Darklords has Test after Test where failure leads to instant death. Not ENDURANCE damage, but death. Some of them are fairly understandable choices, too, and in some cases they are unavoidable due to certain areas' railroading (the forcing of players along a specific plot track regardless of what their characters want to do). There is one long dungeoncrawl consisting of alternating Tests and combats that goes on far too long, and it's almost immediately followed by a VERY difficult combat.
The adventure also warns that a "terrible sacrifice" is required at the end. I ran the situation past a couple of experienced roleplayers. Both of them came up with alternate solutions requiring no sacrifice and having a greater chance of success ... neither of them even CONSIDERED the possibility of doing what the adventure obviously assumes they'll do.
There is also a problem with the interpretation of the Kai Code in this module. Many of the Lone Wolf books require you to make difficult moral decisions, and it's good that the modules for the multiplayer version offer the same. Unfortunately, the writer's interpretation of the vows of a Kai Lord ... does not match the interpretation in the books. In fact, in a couple of the original gamebooks very similar situations are presented and the player is PUNISHED for acting the way that this adventure absolutely requires.
1 - The Kai Code forbids hoarding WEALTH. Kai Lords who reject offers of weapons or don't search treasure chests because that's "not what they're there for" don't end up obtaining vital keys and objects for later on.
2 - The needs of the many outweigh the needs of the few, over and over. There is a specific puzzle in Book 2, in fact, where worrying more about protecting the people than accomplishing your mission kills Lone Wolf and dooms all of Sommerlund.
The book is also filled with typos and grammatical mistakes. Granted, this doesn't affect the quality of its material, but it is an indication that this book did not see nearly as much editing as it needed.
Some parts of this book are very useful, particularly the first couple of scenarios. I wouldn't run anything after that, though -- not without changing so much that I might as well have just written an adventure on my own. I'm hoping this isn't indicative of what to expect from future published adventures.