This is a great supplement to have. The creatures inside are all interesting and fit their theme well. Some of these figures might fit into a given campaign, but I'm looking forward to using them as ways to fill out sessions where some people have to miss a session that would be too story heavy to run without them, or when I haven't had time to prepare a full session for the week. What party doesn't want to find out if they could defeat Ghengis Khan or the Easter Bunny?

It's great if you want a bunch of NPCs (and you can easily just rename them if you don't want a historical or fictional character in your setting, which is what I plan on doing). However, because these are characters based in real-world history or literature, they aren't overly "fantastic" or magical in nature (except for the few monsters in there, like Black Shuck). In a D&D-type setting, which is usually rife with magic, that makes them fairly odd.

Also, despite what the table of contents says, the warlord Fighter archetype is not a playable archetype. It's actually a list of abilities originally from a warlord (class, I assume), "created by one of the 5e designers." I'm guessing they included that as a way of stating that the abilities weren't their own design. If you were looking for an additional Fighter archetype for your LU game, you won't get it in this book. (Of course, Level Up has the Marshal archetype, which is the Warlord under another name, so you won't be bereft.)