The Shadow Campaigns - Muskets and Magic
Django Wexler is a strong new voice in military based fantasy, The Thousand Names follows the story of two very different soldiers facing impossible odds under an eccentric new commander. Captain Marcus d'Ivoire was the senior-most surviving officer after a bloody rebellion forces the Colonial Army into retreat. As a common born graduate of the War College he never imagined being in charge of a regiment so he's relieved that the Royal Army is sending a colonel to take charge. Winter Ihernglass is a Ranker, one of the rank and file. Most of the Colonials were sent there because they were an embarrassment or did something criminal but Winter wanted to go where no one would ask questions because "he" is a "she".
Then Count Colonel Janus Valnich arrives with three thousand untrained troops with orders to put down the rebels who vastly outnumber them. Thinking that Captain d'Ivoire asked for names of soldiers for a "special" duty meant almost certain death Winter's sergeant sent her name up. Instead she is promoted to Sr. Sergeant for a company of the new recruits. This allows her to escape a sergeant who hates her but she's worried that her disguise won't hold up to additional scrutiny. Marcus expected that the Colonel would look at the situation and decide that their only option was to pull out entirely but Janus fully expects them to succeed.
The colonel may be a brilliant military mind but he's also an enigma who admits that he opposes the powerful Minister of Information, Duke Orlanko, that he claims is allied to a hidden sect of the church that uses demonic agents. His true goal in the colonies is to prevent Orlanko and the Black Priests from getting an ancient artifact known as The Thousand Names. The Duke's agent tells Marcus that Janus wants it for his own power and that the Black Priests are trying to save the world from demons. The demons are each unique and can grant their human unique abilities. The first we see is one that can heal the carrier and grants strength but others are more like superheroes who can control fire or grant extraordinary vision etc. The Thousand Names are just that, the known names and properties of demons and by speaking the name someone invites the demon to join with them. Most don't survive the attempt even after preparing for decades.
The books focus on Marcus and Winter in their various struggles and we only see Janus from their perspectives. To them Janus is a both a hero and a source of consternation because he never reveals more than he must. As the series goes on Janus is also a symbol of the new Queen's determination to reduce the power of the aristocracy and give more power to both the common man, and the common woman, because he promotes officers based upon their competence. Their country is going through a revolution similar to our French Revolution combined with a bit of feminism. Winter also brings in the modern idea of a transsexual since she's far more comfortable in her male guise even after the truth is known to some and women have been accepted into the army.
So far there are four books, The Thousand Names (2013), The Shadow Throne (2014), The Price of Valor (2015), and The Guns of Empire (2016). The first book only introduces the demons at the end and that becomes more of an issue as things go along. The Shadow Throne adds Queen Raesinia to our cast of characters and the focus is on the revolution. The Price of Valor is the Reign of Terror so to speak, keeping to our French Revolution model. Janus supports Raesinia, therefore so do Winter and Marcus, despite the fact that she carries a demon, the Eternal Warrior, and cannot die. Not to worry, she's on "our" side, but she only wants peace and Janus is determined to carry the war to the heart of the Black Priests and destroy them all. And still the Black Priests say Janus is the true threat...
All four are also available as audiobooks narrated by Richard Poe at 4-5 stars.