The first half of this was fairly enjoyable. But then...
it felt like the author changed his mind about where the story was going and did a 360.

Spoiler

He's back to being undead, and being an undead minion, and having quests from the destroying plague to destroy the world

. Book 1 and 2 was also such a slow pace, leveling wise, yet still ahead of everyone else. Yet around the 70% mark of this book, the MC cheesed a boss and gained over 60 levels.. he was now level 100. But by the end of the book, he was closer to 200 and I just... why? Was too excited to take the fight to the "Big boys" that the author just skipped an entire book of dungeon crawling and leveling.

Not to mention, now that they're outside of the sandbox apparently there are some different rules. For example, the MC ran into a dungeon and went "If they enter after me now, atleast they wont enter my instance" while in the sandbox if someone was inside NOBODY could enter? I don't know if the author forgot that, or if the rules are actually different. There were a few moments like that which was confusing