One thing I have always questioned about typical fantasy villains is the fact that we rarely see the people who would support the Saurons and Ganondorfs of the setting. In real life, in order to raise a vast army of fanatical follows, you need to have fanatics. Here, the Darkmage is someone that his followers still revere and is specifically revealed to be the hero of an ethnic minority that is persecuted in the larger setting.
Lira is someone who doesn't have any particular ideology. Abandoned in an orphanage after her mother's death, she proceeded to suffer immense abuse before running away to become a street thief. This taught her the value of comfort, luxury, and power. She's not interested in whatever her grandfather was fighting for, if anything, but just wants to secure her own future. It's an interesting take for a protagonist and one that intrigued me.
The book is written in an asynchronous style with frequent flashbacks between the "present" where Lira is a student mage working with the Underground and her past growing up in poverty. Lira doesn't make friends easily and a large part of her appeal is the fact she's quite manipulative as a heroine. Most of the people she meets are ones that she considers to be tools first and allies second, rarely ever approaching the status of friends.
There's plenty of traditional fantasy for those who like such things, though. There's monsters, strange locations, weird magic, and sinister plots afoot. Those looking for a hard magic system will be disappointed as the only things we find out about sorcery is that it is hereditary, is determined by your lineage, and a skill that must be heavily practiced in order to be used effectively. Lira has immense potential as a sorcerer but doesn't come to her own until she starts getting training by the very group that cast down her father.
World building-wise I didn't have any problem with the setting. The politics were simple enough to understand but with enough nuance that I didn't think the world wasn't more "grounded" than your typical fantasy setting. You get the sense that J.R.R Tolkien stories of good vs. evil are told about these conflicts but the losing side has a very different perspective on it. Even then, there's probably more than a little truth to the darker claims about her grandfather than his supporters admit. Not that Lira cares.
In conclusion, I found Heir to the Darkmage to be an entertaining and well-written fantasy novel. It is about a young woman coming into her power and own but in a very cynical realistic way. Lira reminds me most of Raistlin Majere over more traditional fantasy heroines but manages to do a better job at pretending to be affable than he ever did. The book manages to weave an interesting tale and create a believable setting for its adventures.