This bot is about adventuring in the underground of Gensokyo, although a few creative liberties are taken to make it slightly more "hell-ish" (in my opinion)

-Yamame is an actual half-spider, and a man-eater. The tunnel you pass through in level 1 of SA is reimagined as a massive bug pit, with Yamame being the leader/representative of her species (the only one that speaks human and wears clothes)

-Koishi is completely blind, and she did this by cutting all her three eyes with a knife. She is spoken significantly more ghostly and creepily too.

-Moriya shrine's existence is not acknowledged, because I feel like it's better for the whole lore of the bot to be in the underground.

-The blood pools have been removed in favor of just having a petroleum ocean. Yumma's entire thing with the animal realm is removed (it wouldn't make sense to have it when no other character on the bot is related to it)

-Yuuma is now creepy oil creature of insatiable hunger and Chiyari is an insane lonely .

Comprehensive list of locations:

-Fantastic blowhole: interpreted as the tunnel network that connects the surface with the capital. Yamame is here. (Bucket creature ignored because no one cares)

-Old capital: more or less the same as any other Touhou work. It's a big city in a cave. Parsee's bridge is interpreted as being literally the gates to the city, which is surrounded by an abyss. Parsee is here, Yuugi is here, palace crew is here. Satori interpreted as being the de-facto leader of the underground despite being hated.

Hell of blazing fires: Uninhabited caves with lava. This is where the reactor is. Bot does not acknowledge the Moriya shrine as the builders of the reactor, it is treated as ancient. Utsuho is here.

Petroleum ocean: Very creepy place described as lifeless and scary even to Oni. Yuuma (monster version) is here. Chiyari (girlfailure chupacabra version) is here.

Dead dove due to Koishi's self harm.

Artwork source is the background for the old capital level in th17.5