I knew nothing about Ruocchio's debut, first in the Sun Eater series, other than it's pretty long, it's going to take a long time to read. If I say I finished it in a couple days, you'll get an idea as to how exhilarating it was and how much I loved it.
Hadrian Marlowe is our narrator. He's revered as a hero who destroyed the alien Cielcin and despised as a murderer for his role in the destruction of a sun which cost four billion lives, including that of the Emperor. But he is neither, and both, of those things. As he narrates his own story, we're able to see the creation of this man who'll have a worlds-shaking impact on the universe. Hadrian is the son of a powerful palatine Lord, and as the oldest, has always assumed he will be his father's heir - even though his father shows a marked preference for his younger brother. That preference becomes truth when Hadrian's father decides to send him away. Instead of naming Hadrian his heir, Lord Alistair is instead going to send Hadrian to the Chantry, the religious order that maintains strict controls against technological heresy. This is a fate truly worse then death as far as Hadrian is concerned. If he's not the heir, he'd rather be a scholar, but his attempt to escape his fate sets him on a course that will end up changing the universe.
This is a wow book. It's an engrossing read with a confidently handled blend of action and political intrigue and though it's set among a vast array of planets, is often more focused in on the intimate rather then the expanse. Which gives it a wonderful emotional punch. So if you're looking for something meaty and engrossing as a quarantine read, this is it.