These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Well World
Nightmare Fuel: Resets. Let's just think about what one entails: not only will you die, everyone and everything you ever knew or will know will simply cease to be, and will never have been. Your friends, your family, your homeworld and star system. Gone. All of it, everywhere. This is the GOOD outcome, and you can take cold solace in the fact that if everything goes according to plan (which it might not) you and your world will be reborn and given a chance to avoid whatever problem caused this in the first place. Now, the harder side of things: Survivors. Survivors will have to live with the guilt of having survived something that the entire rest of the universe (barring others like themselves) vanished from. Survivors would be the only ones to remember everything that disappeared. And what does surviving mean? It means trusting and being trusted by a Humanoid/Eldritch Abomination that can fix everything. It means being dropped onto a planet where almost everyone is a monster, and you will be forced to become one yourself. Then, you will join a war against some of these said monsters (many of which can do far worse things than MERELY kill you) to get this Abomination to the Well of Souls. All of this happens before the reset itself. Congratulations, more guilt! Not only are survivors in the only group who will remember the old universe, they will share in the responsibility of kiilling the Quadrillions of people who were still living there. What's the reward for all of this? The chance to live a full lifetime as whatever monster you become, in primitive conditions, knowing you're helping to create a population which may just come into conflict with your old species at some point in the far distant future. It's easy to think with all the fighting and monstrosities that Chalker was channelling Revelations in writing the Legacy duology.
Even worse than that- in one conversation Brazil admits that the math allows for the possibility of an afterlife. Then says it doesn't matter as those would be wiped out by the reset too. So not only are you erasing everyone currently alive from the universe, you're erasing everyone who has EVER lived in that universe.
Paranoia Fuel: The Yugash, which were the inspiration for mythology about Demonic Possession. They're an energy life-form that can inhabit a person's body and take control of his or her actions. You can't see them in bright light, and being energy creatures, they can pass through just about anything. One of them actually brightens the lights in a room just before attacking Antor Trelig's party in the Northern hex of Bozog in Quest for the Well of Souls.