So... The spider is now a god. She got that way by eating a bomb that could have blown up a continent. She was always jealous about the demon lord having Gluttony skill, which is one of the 7 Deadly Sin skills. Spider chick has Pride and Sloth.
Meanwhile, the Demon Lord has Gluttony.
Envy is the little Vampire girl, and Wrath is the Goblin -> Ogre -> Ojin (magic guy). He makes magic weapons because of his skill.
Oh, and that crazy kid from the school that tried to kill the Hero's brother has Lust and Greed.
(1)Pride (2)Greed (3)Lust (4)Envy (5)Gluttony (6)Wrath (7)Sloth
Anyway, after the spider chick became a god, she went full person mode. She also lost all of her skills. She's now just a person, that can't use skills at all. In other words, she's useless. Eventually she learns how to make web, but it's terribly weak. Then this kid gives her alcohol, and suddenly she figures out how to use magic and she's (mostly) strong again. I really like this book.
Oh, then they dropped a huge bomb shell on the readers. After becoming a god, Administrator D invited spider girl (white) to come visit her once she figures out how to get there. Once her spells are mostly back together, she teleports over to Japan just to see her house again. It's been 15-16 years in the spider's world, but it turns out only 6 months have passed in Japan. And when she gets to her house, she finds out that it belongs to Administrator D. See, D is the real girl that spider-chick thought she was.
Of the 26 people that died in class and were teleported to that new world, only 25 were human. There was also a small garden spider that died. And because D didn't want her boss to realize that she had been fucking around on earth instead of working, she captured the soul of the garden spider, and put all of her memories (of being a human) into it. Then resurrected it as a spider in the labyrinth.