Dungeon Reset - Chapter 257

Okay, now I have some questions.

1. The lich was made BY ARTHEA, does he not remember her?. Also when she was guarding the tree of life. She didn’t seem as old, so I thought she didn’t make him yet. But then she goes to her own house and says “what is this place”… ???
2. She can’t use the shadow attribute?? She INVENTED the shadow arts. Not only that, but she invented it in her lab. Then she fights the end dragon? Or does she fight the end dragon then goes to the lab and starts studying by herself because all the people died off. But it’s not her lab? But the lich also has multiple masters that isn’t her?
3. If all life is dying, how would there be shadow cats. But also how would she teach the shadow cat magic if she doesn’t live there? So it hasn’t watched her, but also she can’t use shadow magic so in the end the cat doesn’t get the shadow magic bell?

Either it seems the past can’t influence the current timeline. Or what has already happened in the timeline. Like, the book of life is full of plot holes, where someone went to the start of the book and rewrote a bit they didn’t like. But the end of the book where the mc currently is, is unchanged. So he lich the mc met had only 1 master and the whole 4th floor was made around the story of the witch. THEN he went back and changed stuff, but the 4th area was already made about the witch and still is. So only the memories of characters changed. That would kinda make sense.
Otherwise, massive plot holes, I don’t know what’s happening. Get out of my skin