I ran across this series in a Barnes and Noble, and picked up the first three volumes on a whim. I will say that the first volume was a little weak in terms of developing the main character, but that may be because of what appears to be a partial amnesia that these new "demon lords" have upon being "created" in this fantasy world. It's immediately clear to the reader that they were probably brought there, rather than created, but the rest of the story is fairly interesting, especially with the system used for these "demon lords" to create dungeons and "monsters" to inhabit them. Since anything not fully human and with more than minimal power is defined as a "monster," the term gets used oddly. For instance, elves and dwarves qualify as monsters, as do dragons and skeletons.
My only odd quibble with the art is that the writer and artist don't seem to agree on what kind of story this is. The female characters have a wide range of types, but the bustier ones tend to wear less clothing, with lots of cheesecake art. I'm okay with that, but a few times it's a little over the top for the stated "teen" rating, not because of the art as much as because of the notes going with it, like the "pinup" piece on page 159 and the descriptive note. The note came across as being on the tacky side, and it's the kind of thing that could turn off some readers.
From the very start, the main character looks like a game-changer in this weird setting, because both his powers and his ideas are way outside the box. So, the story looks very interesting.