Pathfinder Campaign Setting: "Undead Unleashed" [RPG]

Undead Unleashed is a pretty straightforward book.  Essentially, it's a collection of fifteen four-page entries on (mostly) high-CR named undead NPCs.  Half of each entry is made up of a picture, full background, and stat block for the NPC.  The other half of each entry is a map and room-by-room layout of the undead's lair.  The creatures and lairs are situated in the Inner Sea, but most could be easily adapted to other settings.  I wish they would have included an adventure hook section.  Given how powerful these undead are, I assume most would be used as campaign "bosses".  Some of the entries also include a new magic item, disease, or some other crunch.  Six different writers are credited on the book so there are definitely some differences in approach.  Here's a brief rundown on the creatures included:

* Arantaros (CR 20 ravener): A dragon alchemist who failed in an attempt to replicate the Sun Orchid elixir for immortality, and thus decided to bargain with a demon lord to achieve eternal "life" another way.  It's an intriguing backstory.  Arantaros' lair is high-level indeed, though they ran out of room to describe the treasure in Arantaros' horde.

* Arnlaugr the Fearless (CR14 draugr): A famed Ulfen adventurer who got in over his head and now serves in death as the guardian of a powerful witch.  The lair is pretty mundane, apart from being mostly underwater.

* Erum-Hel (CR23 mohrg):  You know Erum-Hel is tough, as he makes use of Mythic rules!  This guy could easily be the big-bad for an epic campaign or a new antagonist after PCs finish an AP by roughing up some CR 20 wimp.  His backstory is tied intimately into Iomedae and Tar-Baphon, and his lair is very cool and memorable.  One of my favourite entries.

* Imaloka Ghalmont-Neverhome (CR22 banshee): There's a fantastic backstory for this banshee, though it would be hard to bring out most of the flavour into an adventure involving her.  As a resident of Sarkoris/The Worldwound, she would make a surprise non-demon foe for adventurers to face in that area.

* Jolanera (CR17 nightwing): Another backstory tied strongly into Tar-Baphon.  Unfortunately, this nightwing doesn't have much of a personality.  Its lair has some interesting foes though.

* Meyi Pahano (CR13 lich):  This lich has a cool backstory tied into both Lirgen (the drowned lands beneath the Eye) and Eox (the planet of undead).  She's a diviner wizard, and thus a different type of combat threat than many others in the book.  Her lair is sound.

* Mirik the Drowned (CR3 ghast): One of the very few low-level threats.  Mirik is nicely integrated into Absalom's Siphons district and could be the base of a good little story arc.  I like the sewer gator zombie!

* Mother Comfort and Poor Eledia (CR3 allip and CR 4 attic whisperer):  A classic haunted house location with a really said origin story.  A new magic item introduced here, the ghost mirror, looks really good.

* Ordellia Whilwren (CR10 ghost): A good-aligned undead!  This violates one of the "rules" of Golarion.  Nonetheless, I like the character's integration into the history of Magnimar and the really interesting story seed of what it would take to set her spirit free (getting a Varisian elected leader of the city).  There's even a Season 10 PFS scenario that uses her lair from this book.

* Prince Kasiya (CR12 vampire): I wish I had read this entry before reading the Pathfinder Tales novel King of Chaos--it explains so much!  This vampire sorcerer has a fun backstory as an (evil) former member of the Pathfinder Society.  Stats are included for his flying chariot.

* Razinia (CR7 ghul): I could see a good story arc set up around Razinia and her domination of an important oasis (and caravan stopover) in Qadira.

* Rudrakavala (CR15 devourer): Great, creepy artwork for this guy along with a cool premise for his existence that creatures a natural adventure hook.  His lair is nestled into an extremely difficult environment to traverse, so adventuring parties that focus too much on combat proficiency may die before they even get to him.

* Seldeg Bhedlis (CR17 graveknight): One of the six Knights of Ozem twisted by Geb and sent to steal Arazni's body!  Now serves as a general and spymaster.  The lair is pretty bland, unfortunately.

* Walkena (CR16 mummy): Divine undead child-god and ruler of Mzali in the Mwangi Expanse.  Walkena kills all foreigners and tolerates no dissidents, and I like the idea of the PCs having an entire city as their enemies.  This entry has the only new feat in the book, but it's really just for NPCs.

* Wight Mother of Isger (CR19 daughter of Urgathoa): This big-bad murdered the entire town of Finder's Gulch in Isger and now uses it as her headquarters.  As a growing threat in the region, she could make a good campaign villain.

Some general thoughts:  1) The cover art is really cool, as Kyra tries to fend off a lich and its minions--I hope Sarenrae comes through!  2) The interior artwork of each villain is very good--maybe not Paizo's best, but definitely strong; 3) The cartography on the maps is mostly pretty bland.  Overall, this book definitely adds to setting lore.  However, I think it would probably really only be useful to homebrew GMs who need inspiration for a high-level undead antagonist.  Even those GMs wouldn't make use of the vast majority of the content in the book, so I wouldn't consider it an important purchase.