TL;DR: This novel is like having a steak dinner after only eating hamburger helper for months.
First off, the writing itself is on point. Just talking about grammar, punctuation, and spelling, it reads like someone actually proofread the chapters, and there aren't noticeable errors that distract from reading! Many available webnovels seem to suffer from a lack of proofreading, but this one doesn't. Even if this author doesn't actually proofread.
In addition, the author's voice and varied vocabulary ensure good sentence variety and proper flow in each chapter all the way to the end, upon which one realizes they've read a lot, but still want to keep going. Once again, good flow is often hard to find in webnovels, so this one is a breath of fresh air. Or rather, a bite of sirloin steak.
Plus, the characters have tangible character development--the big brain imp from the first 100 chapters is very different than the one now. Not just in power and figure, but also in what he values and how he reacts to events now.
Ok I'm tired of writing now--it's a good book, story good, characters good, author good, I def dont regret spending 3 days reading all the way through. Though my wallet hurts a bit, I'd do it again.