A good location fo the end of a quest, every gm should have this in their book, just in case. Gygaxian naturalism with a sense. It's okeish to good to me. 

I'm starting to feel like a broken record about bad printers and poor eyesight when viewing documents at scale. This one isn't the hardest though thanks to the clean contrast from print to background. Just a little small for my liking when I scale it to print size. Overall, it feels clean and well laid out.

The overview of what is going on (known, unknown, and GM only) seems solid and easy to follow. It's not doing anything unheard of, but it doesn't need to either. If I was going to have one thing change here it would be adding bold words to call out key elements as I skim it over again in the future. Draw my eye to what really matters.

The legends all sound like log lines for a book. I mean, they are legends so I guess. Feels less like something I hear from a person and more like something I read from an author trying to offer a single sentence synopsis. Depending on who you ask this is either great or underwhelming. Also, I have to assume the typo was D6 rather than accidentally cutting away the 5 and 6 entry. Random 'encounters' is really not. It's random events honestly. There's only one encounter in the list and it's just an interaction. Nice picture under these. Simple, but evocative.

Immediate impression of the map is that I love the absolute number of directions someone can take back and forth, zig zag, etc. Visually, three rooms are laid out identically which I am sure is entirely logical, though a bit dull to imagine. Option of rooms doesn't mean a lot mentally if every room is just the same room after all. I'm sure you give them a bit more life in the descriptions in the key though. I'd love if the art of this map matched better with the rest of the document.

Sister Arista has a mirror mentioned here, but everywhere else you note a crown. Old version missed in the edits? Otherwise the vestibule serves as a reasonable foreshadowing location. Gideon is pretty strait forward. Interesting that he doesn't attack the dazed players, but mostly strait forward. If you defeat him here, does he resurrect to appear in the encounters or do I just skip the only encounter on the encounter table if he already got defeated? Also, that orphan line cutting over to the next page is something you will want to address. If there's anything you can cut or move just slightly to make sure it stays on the same page as his other stats, the better. This orphan is worse than normal because instead of just being on the opposite page or another column, you let it jump to the back of the page if this were printed. Just to keep track of his stats, I am in theory flipping the page over mid-fight. It's a nitpick, but it speaks to intent.

I don't see any stats or mention of the good sister's body. Since the other two guardians are still here (well, one person and one sword, but yeah), this feels like an oversight rather than intentional. With the nature of this puzzle, I can see certain players absolutely failing to figure it out. Having her here (even dead) might offer a clue. I'm also realizing there will be players who find the objects of each room and assume these are the relics. Nice.

Sword room is probably the roughest one for combat so far. A few good rolls could make Sever a really nasty situation. Odds are low, but I could see this absolutely wrecking a few people with some really bad luck I have played with. Not a bad thing, just something I as a GM would want to keep in mind.

The reliquary changing is interesting. Foreshadowing again, as well as making it clear what is going on when they win over one of the rooms. With two rooms being pretty easy to figure out, they might default back to Arista's room towards the end and just spam ideas until they figure something out. Assuming of course they don't just leave with the false items. That keeper being immune to non-magical items is a rough situation depending on the player load outs. Could make for a tight fight as well. Once again, not a bad thing. Something I would have to assess when seeing the setup of the player characters prior to running this.

The bell and crown are pretty balanced. The sword feels a bit too strong for the negative it imparts. I think most players would be smart enough not to go using it constantly, but having a way for a level 6 character to insta-kill a level 20+ monster at the cost of a single permanent HP is pretty extreme. I think if I was using this, I'd also add it doing some number of damage to everyone in a 'far' range. Nothing insane, but enough that most level 2 and below NPCs would instantly be killed. It reinforces the thematic elements and the visual from the scene in the sword room. No saving the townfolk by just stabbing the monster rampaging through town. You'd need to be smart enough to get it away from others first. Adds a little more thought to the insta-death situation. Especially without a roll to prevent that instant death.

The little note about treasure is fine by me. I know some people throw up their hands in situations where they can't get treasure/xp. Not I. I enjoy moments where a concept is made clear and a lesson may be taken away. Honestly if they're that hard up for loot, I am sure there's a bunch of things they could walk out with to sell off. Either way, overall a solid short adventure. My biggest issue is the lack of meaningful encounters. At least one of those 'encounters' is just a free pass on solving a room. Overall a solid entry. Easy to see where the title was applied, easy to find things when I am looking for them. Some bold call outs would go a long way and a bit more to engage with wouldn't hurt. Thanks for the clear effort.