Also a friend in my Ghosts & Japes discord server helped point out how to upgrade the wand's power. If you want, I could invite you there. I feel like with your knowledge and ability to look through the files, you'd be a perfect fit there
I found out how, and I got it. Though its very difficult to do so. All you need, is a new run in Hardcore + Save Deletion + All three challenge statues activated + The Drill. (Make sure your drill is maximum durability or close to that. Because otherwise you're kind of screwed)
Make sure you make it to Dilapidated Halls and encounter the hooded figure at least once (You can reload the game if needed but DON'T close out of the game afterwards).
Once that is checked off, head to floor 11 in the Halls (Works for any hall but the first one is the easiest) and once you reach a treasure room (Typically to find the key or compass), continue to drill north as far as you can until you reach... the room... Afterwards, you get the sword.
What do you mean by "hooded figure"? Is it a jump scare or what? I don't want to do a Hardcore run, and get screwed over because I can't figure out the exact details of what I'm supposed to see. Is it when that weird thing descends on you and you get transported? Is it Evil Plushie? Is it that thing I think I saw? What Am I looking for?
It is the large monster with the white beaming eyes and huge dark blue claws that descends on you.
The hooded figure is the seer with the black & red robes with the red eyes that you sometimes and see in paintings. However, he only shows up in Dilapidated Halls, and has a rare chance in doing so. (He kills the music and appears for a split second when he shows up. If the music is killed and you hear an evil laugh. That means the Seer has appeared)
You don't have to be in hardcore just to have either the Seer or It appear. If you just want the "Had an unpleasant encounter" achievement, all you need to do is Encounter "It" at least once in Dilapidated Halls (You can also see a painting of "It" while you're in the halls, this is just as a way to make it easier to see what "It" looks like)
However, if you want the "Prove Your Worth" achievement. You'll need the Seer to appear in Dilapidated Halls on Hardcore with all 3 of the challenge statues active (No cheat statues active), You'll also need the drill (Maxed with durability btw) by the time you encounter the Seer for the first time (Don't close the game if you encounter the Seer otherwise you'll have to have a chance to encounter him again)
Is the Seer really that hooded figure? The music for 100% Achivements says the Seers smile upon you. Unless the cheat statues are good seers and the challenge statues are evil seers. More importantly, I saw this playthrough where it seems like the Seer dosn't show up at all, in order to get that run.
So...are you sure that you need the Seer, or did it just happen to show up on your playthrough?
As far as I'm aware, I needed the Seer to specifically show up in order to achieve the "Prove Your Worth" Achievement. After that, I went to floor 11, reached a treasure room, and used to drill to dig as far as I could north (On Hardcore with the challenge statues active), then after reaching a hidden area with those conditions met. I got the achievement and the best reward you could ever get in the game that'll stay permanent (So long as you cleared a floor after getting the reward for completing that achievement)