Quote Originally Posted by understatement View Post
Here, Celia mentions Dorukan has disappeared (aka died) 6 months ago (which also matches SOD's time stamp). And here Celia mentions the Cloister disappears and reappears with Xykon, but doesn't mention any breaks in between. (and Xykon couldn't have casted it after Celia departed the Dungeon, since Azure City was able to scry on the Order).

So, is it inferrable that Xykon's maximum level is ~26 weeks, or 26-27th level? This number also matches some of Xykon's higher-end level calculations.
Not really, Xykon moved into the dungeon pretty much immediately after killing Dorukan per Start of Darkness. Maybe it took a while before Celia noticed him and his minions.
Keep in mind that Celia's first appearance predates the Snarl plot, so any inconsistencies with later stories do not necessarily have a deeper meaning.