Aside some troll missions or unfinished beta stuff I have to say this is the worst FM I played so far.
While the idea of it sounds interesting the mission itself is really bad in most aspects.
The whole level design is a confusing maze, and certainly not in a positive way. There are also too many spots that are bright but shouldn´t be, so sneaking is in parts difficult or impossible.
There are also some gamebreakers, you can fall into a waterhole where you can´t climb up. Also I had the mission fail once on Expert due to the non-killing restriction as a knocked out mage fell into the lava after reloading(fortunately I was able to pick him up).
The design of rooms and areas is really boring and repetitive. You see the same objects over and over again.
Then let´s talk about the mage area. You can only reach it over a underwater section and breath potions are necessary if you want to survive. While there are some in the mission be careful in what order you do the objectives. The mages area is really boring designed, empty and uninspired. Comparing the original mage towers to it these are much better despite some flaws.
Finding loot can also be a hard task. Especially because there are so many empty rooms and areas with nothing in it. And if the loot is hidden, not in really interesting places.
Overall I can´t recommend this mission at all.