In this volume, picking up after the previous one, our protagonists are suffering mild PTSD from the fact they witnessed the biggest and most heinous massacre of orcs which has occurred in a century. Worse, they were indirectly responsible for the crime and have been outlawed as part of the Heroes' Guild's attempts to cover up their role in the set up. Unfortunately, our heroes aren't very good at trying to make up for their mistakes. They've wandered around trying to find the orcs who survived and have absolutely no luck. They do soon get an opportunity to save the world by stopping a Liche King's seemingly unstoppable army. Just, there's the slight issue they're not actually good enough or strong enough to do it.
The Dark Profit Saga is a unique combination of modern political and economic satire with dramatic examination of prejudice plus gutbustingly hilarious humor. The closest analog I can think of is Terry Pratchett's Discworld where, comparatively, I think it stands on equal terms. That's praise I don't throw around lightly. These books are every bit as funny as Pratchett and has just as good an amount of world-building. The treatment of capitalism is critical but it's not attacking the system of making money itself but the greed as well as criminal lack of responsibility or consequences even when they break the law.
Basically, one of the prevailing themes is the corrupt bankers and investors behind the Heroes' Guild are always willing to bend the rules to their favor as long as it means more revenue for them. Whenever there's a problem, they blame F.O.E.S (Forces of Evil) or beat the drum of racism against against NPCs (non-evil monsters). They even throw their legitimate enterprise NPCs under the bus as long as it means more for them. I'm not a big fan of Wallstreet so this kind of nasty criticism and accusation of race baiting didn't bother me.
I was a big fan of one plotline where a Wall(street) banker is "woke" to the injustices of the system where the Wood Elves, local family of Trolls, and other NPCs around him are slowly killed off. We also see how the Orc survivors are dealing with the temptations between turning back to the "Old Ways" for vengeance versus trying to make a fortune as aggressive bargainers. Mind you, while the author sides strongly with the orcs who don't want bloody revenge, I'm not sure the ones that do are in the wrong since the people who TRIED legitimate business were murdered for it. Why, exactly, is going back to it a smart decision?
The section from the perspective of the undead horde is also hilarious. The Liche is trying to figure out ways to kill everyone in the world before adding them to his undead army. He'd very much like them all to join his organization willingly (so he doesn't have to fight them). That means trying to make better pamplets as well as slogans to persuade people to serve him. The cowardly head of the city guard who deserted his post, only to run accidentally straight into the armies of evil, provides an interesting perspective on the whole thing.
As for the main party, we have development in ways I didn't expect. Gorm the Dwarf tries to deal with the loss of his two best friends as well as his attempts to be a hero despite being very bad at it. Their elven ranger is addicted to salves as well as the object of affection for a troll. The mages have to deal with the fact their forms of magic are completely incompatible (or are they?). Plus, one of them is the Liche King's son. There's even a Bard in deep debt to a magical artifact hook that is also a crime lord.
In conclusion, Son of a Liche, is a great novel. It has a lot of good character development for the protagonists, interesting twists, and detestable villains. I personally am hoping that Johann the Paladin eventually gets his (since he's a terrible example of his class) but we'll see how that goes in the third novel. This is a truly well-realized fantasy world with likable characters and a wide-variety of references for people who love D&D, MMORPGs, and fantasy in general.