It's easiest if you just look at the preview pages:
https://www.kickstarter.com/projects/daishugars/the-monster-overhaul
Scroll down to the mercenary entry. This is one of the leaner ones, but it takes what's normally a pretty rote Monster Manual entry and instantly gives you the color needed to make it something other than "uh, it's 2d4 mercenaries, I guess."
I wish the previews showed some of the better entries. (The DriveThruRPG preview weirdly just shows the table of contents and information on how to use the book, which is a really poor choice.) But the dragons entry, for instance, has a chart that lets you take the stats for young dragons or elder dragons (the two core stat blocks) and make almost two dozen variants of each, including all the classic D&D ones, but also steel dragons who breathe out a blast of swords, for instance.
The vampire entry goes over three pages and gives you everything from what sort of supernatural powers this vampire has to their appearance, who their servants are and even a complete castle to drop them into.
There's a bunch of posts about the book here on ENWorld that go into more detail.