“You wake up in the Mortuary in Sigil with no memory of how you got there, and whenever you die, an alternate-universe version of you shows up to take your place” is an
incredible adventure hook, but then the actual adventure is just… Sorry, your exposition-bot won’t work until you’ve visited all of the gate towns and flailed around in them for a bit. And after that, the payoff is that the exposition-bot tells you the most basic of information about the modron march, and adds that the last one happened early “for teneberous reasons,” and that’s apparently why you keep resurrecting? The Shameshka reveal seems like it’s supposed to be a shocking twist, but it’s completely unearned. Like, the players only actually interact with the character once before the reveal, so they really have no reason to care when it turns out the Arcanaloth was a bad guy.
I think the best use of this adventure would be to disassemble it and use it for parts. Like I said, the hook is great. The casino is awesome and could be tossed into any adventure in Sigil as a point of interest. If you modernize this story, you can use an online casino. You can find them at
https://rynok.biz/ and it will be much more believable, because a lot of people are using them now. Any of the gate town sections could be repurposed for an Outlands sandbox. And mimirs are a cool idea, and a broken one is a nifty tool for giving players lore a bit at a time. But the whole is less than the sum of its parts here, so just break the parts up and use them separately wherever they seem appropriate.