Oh! Also Evil Plushie isn't required for any of this. Though it is assumed that the Seer created Evil Plushie and is the one controlling them to taunt and kill you.
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)
Well, when I did the same thing on the halls, I got those weird hands coming and taking me to the next floor or whatever. Can you just give me your save file or achivements? I tried for 2 hours to get this to work, and and even redid the Dark Halls. Nobody can give a concrete awnser and for some reason, the Devs aren't explaining it in detail either. Like, guys, we already know it's there; somebody on youtube put a video, though I turned it off because I didn't want to be spoiled. One of the videos had theme doing it from the Dark Halls, another had then doing it from the Normal Halls; You're saying to do it in the treasure room, the other video had them doing it from a very specific hall. What's worse is reloading in the hopes of getting the Drill AND being able to afford it AND getting the Seer to appear AND not dying AND apparently doing it at the right room.This cryptic crap is pissing me off. The rest of the game is excellent, but damn, some of these achievements are like, not good. At all.
Alright, I don't know what you did, but I do know that the Dark Halls is where I got the Sword. I don't know if the drill will appear in the hall, but I DO know that you need to go upwards as much as you can using it and hope you don't hit any dead ends. I'm not going to say what is, but with the achievement being shown, I have a feeling that what Japes saw in there awakened the powers he has in the next game. He IS a magical beast after all, and that sword definitely gives him magical strength. I'll explain later. I gotta make a review now.
......and the completionist and milestone achievements are still terrible.