This pdf is 12 pages long, 1 page front cover, 1 page editorial, 1 page SRD and 2 pages of advertisements, leaving 7 pages for the 3 incarnations of Primus Gearheart.
The first page gives us an introduction to Primus Gearheart, how he fits in with the Souk as well as providing dreams to use with Coliseum Morpheuon's Dreamburning rules as well as an extensive sidebox as advice on how to use him.
His first Incarnation (A Ironborn battle sorceror with the constructed bloodline at CR 21) takes up 4 pages and also features statblocks for his CR 4 duplicates (Clockwork human rogues). The best part about this incarnation, though, is that he gets 5 quite cool, new magical items.
The second incarnation takes up one page. (CR 14 Ironborn battle sorceror)
The third Incarnation is a CR 7 lvl 8 Battle Sorceror.
The last page features the "Clockwork Creature" template to create a vast array of minions for Primus.

Conclusion:
Both the interior and the front cover artworks of this b/w-pdf are once again beautiful. Formatting is the usual two-column-standard. I did notice some minor editing problems, though: In the feat lists of all Incarnations the feats "Craft Construct", "Craft Ironborn" and "Eschew Materials", if present, suffer from a capital "B" as a relic behind them.

Fluff and crunch-wise, I wasn't as impressed by this installment as I was with Ahnkar-Kosh. I think Primus would have worked better as either a Wizard or a Summoner and, quite frankly, while his statblocks are neat, they are nowhere near the extraordinaire standard Rite Publishing has set for itself: No Templates have been applied to Primus and where all three Incarnations of Ahnkar-Kosh were quite different takes on the recognizably same creature, Primus felt "only" like a continuation of himself, a normal progression. There is nothing wrong per se with him and his motivation and background as well as the rivalry with the Jack-of-Diamonds are nice ideas, but in direct comparison with Ahnkar, he feels kind of bland. Don't get me wrong, Primus is still a cool, unique character - he's just not as superbly creative, complex and far-out as Ahnkar-Kosh and I could have created (bad pun, I know) him myself with some effort. Thus, due to the minor glitches and lack of templates, I'll settle for 3.5 stars. A good addition to the series, but not an outstanding one.