In the laetus keep castle had the large winged demon drop a cursed blade. The one in the room you go in right after you talk with the dude who drops dead.

for anyone that's interested, i made maps of the last 2 maps just for completeness sake, op you can include these in your list without credit if you want:
https://i.imgur.com/dsKRKfR.jpeg
https://i.imgur.com/knxZVa5.jpeg
[reposting because don't see edit button]
edit: i realized it'd be easier to map of the final map being out of bounds, so i made a basic cheatengine table to facilitate that, too lazy to remake the map myself but anyone else knock yourself out
for best use, add cheatengine as a non-steam game, duplicate lunacid totm's controller config to cheat engine in steam, freeze z values, set freeze interval to 8ms, then left trigger + forward/back to move north/south forcing through walls, left trigger + left/right for west/east, and most importantly left trigger + a/b to float up/down, this lets you access the oob roads in road of ruin
here's the table:
https://drive.google.com/file/d/1JUhbz-dqMigU_SkNYL-Kxn8PiN7Kbsl4

@HyperWing, good catch, something went screwy with the numbers. 29 should be where 28 is, meaning there's a number missing somewhere. I'll try to fix it as soon as I get a chance

Where is #29 in the Aqueduct? I don't see the number on the map.

Thank you so much for that!

@Teroxy The Moth fixed, ty

#16 in The KIngdom of Lyria is not labeled in the key and #26 in the Castle Scawl is mislabeled as #25.

holy moly this is one hell of a guide, crazy work!

@Zuldim If I do a second playthrough, I'll screenshot it. I might be remembering the location wrong. I just remember as I was going along it was out in the open (don't think it was a pickup from a body) and noticing "oh, this isn't on the map". But I'm feeling iffy on the exact location. I think it was about there.

@Teroxy The Moth Added, ty!

@ProgramMax I can't find a health vial in the room north of 7, but it's possible I'm crazy. If you can share a screenshot of the spot I'll check again/add it. Added the Healing Sprig in the T-junction! Thank you again!