As my friend would say - "messy."
There's nothing wrong with wish fulfillment - most wuxia is nothing more than that, some are just written with more finesse than others. But the writing in EMS is stilted and awkward. The dialogue, as Vex said, feels like it's constructed by a five year old. The protagonist is a black hole of charisma.
I've read worse novels, but usually it takes me, oh, 200 or so chapters to really feel the story drag at me to a point where I'm rolling my eyes. I've read more formulaic ones too. I've read more blatant wish fulfillment ones. But something about EMS is special. After only nineteen chapters, I'm tiredly rubbing my face and rolling my eyes. Maybe it's that less than 20 chapters had to pass before we got THREE separate harem flags, one of whom is his (non-blood related) sister, and all of them I want to hear about as much as a case of herpes. I could tell you details about their respective breasts and asses, but I couldn't give you a concrete description of their personalities (pouty and flirty doesn't count, I mean who they exist as outside of their interactions with the MC). I can't even remember their names - or the MCs name, at that. Maybe its the rush the author was in, tripping over their own feet, to hit at least five or so of the usual plot points before ten chapters of the story. Maybe it's the way it took all that boring, bland, formulaic, wish fulfillment and condensed it into the first two dozen chapters. I think that's my main issue, in fact. I don't mind formulaic wish fulfillment novels with bland, one-dimensional characters and a slowly materialising harem. I actually don't. But they usually wash over me, very slowly, over a course of hundreds of chapters, in little bite sized chunks of mediocrity that I could digest.
EMS was an immediate overload of all these things.
I mean, to take a more positive approach, because I don't want to be wholly negative, at the very least this novel makes no pretense about what it intends to be. Absolutely none. Its immediate delivery of all these repeated tropes is very straightforward and it doesn't dawdle around and trick you into thinking it's something more (boy have I regretted recommending novels I thought were pretty great and then three hundred chapters in I just... sigh...) and you will be able to decide very early on whether this is the novel for you. That's refreshing. Props for that?
This is not the novel for me. Maybe it's the novel for you. But it's definitely not the novel for me.
Hold on, let me give a stellar example of the writing. From chapter 20:
"You... just who are you?" The two men's faces were full of horror as they retreated. [...]
"Who I am isn't important. What's important is that there are no grievances between us, and yet you all wanted to kill me. It's evident what sort of people you are. Today I, Xiao Yun, am going to exterminate an evil for the public and erase you all from this earth."
Son! Don't drop a line like "Who I am isn't important" and then proceed to introduce yourself by name! It's an absurd piece of writing. It's like it was just written sentence by sentence with no real thought about what preceded or succeeded it, just based on what sounded cooler.
There was a massive sale on filler content down at the writing store and this author stocked up in bulk. Things that could be said in 1 sentence are consistently said over five repetitive paragraphs. There are other issues with the story, there are always issues with webnovels, but these issues are easily dismissed. Cliche plot turns (barely a twist, a turn at best) ? Tropey, poorly written harem members that indicate a distressing lack of any knowledge or interest on how women actually think, feel, and act? Unnecessary foreshadowing on simply resolved schemes? Yeah. Good luck finding a webnovel without those things. But they can easily be balanced with more interesting MCs and writing, and just browsing the comments of QI shows there are plenty of people who apparently actively like these things.
But the filler. My god, the filler. One very merciless editor who sent back every chapter given and told the author to go cut out a good 60% chunk of it could have saved this novel, but alas, Chinese writers are paid by the word I hear.
I give this story the same amount of stars as the average amount of content in any given chapter. 40% real story, 60% filler.
(Actually it's more of a 20/80 split on average, because when you have literally entire chapters are nothing more than filler, it really messes with the statistics. But you get an extra star for having occasionally interesting enough alchemy stuff to get me to read 113 chapters of this rubbish.)