It's almost 100 years since the Terran Republic was conquered by the Klingon/Cardassian Alliance - and all that Spock's been working for went underground. The rebellion is adrift, without a leader, fighting too many battles on too many fronts, but it only needs a figurehead to unite the factions, to point them in the right direction and to rebuild the world into the vision Spock gained by melding with McCoy back in "Mirror, Mirror".
Rise like Lions isn't the direct successor of Sorrows of Empire, unfortunately. There have been a few books in the DS9-relaunch that play into it, that set up the stage (such as Iliana Ghemor's role on Bajor which kind of jumpstarts the action here, or Kes), so that's a bit of a downside if you come directly from Sorrows. Again, I question the choice by the editors not to include a short "previously on"-section (or at least a list of books you should read previously) because not everyone read every book, and within the narrative, especially here, events remain a bit unclear.
Nevertheless, it's the small details that make this book rather enjoyable: Like Calhoun and Jellico getting on (albeit they did so after the big hiatus in NF as well), Luther Sloan being part of the Terok Nor-rebellion, Picard's insecurity and natural ability to lead, Duras being a good guy here etc. But actually, what happened to Jadzia that she wasn't there? I remember her in the MU-episodes, so there was a Jadzia. Did she die?
Overall the question of the end justifying the means continues here. This time the Alliance comits genocide on the Vulcan slaves, they wipe out whole solar systems to make a point. And the rebellion considers replying in kind... but finally, they don't, they realize that in order to change the world into something better, they can't found that change on terror and destruction. Interestingly, it's O'Brien, backed up by Ghemor, who makes that point, not the Memory Omega people left behind by Spock and led by Saavik.
But the one premise that bothers me most in the MU is the fact that all the people we know actually exist there despite the MU having a hugely different past. And still the same people had the same children, and those children actually turn up at the same locations? Yes, it's fun, but it really asks you to disregard probabilities... especially considering that humankind and the Vulcans have been enslaved and conquered peoples.
If there's one thing I'd wish for it is to see a continuation, because as we witness every day, the transition from rebellion to revolution to democracy isn't an easy one. Does the newly built "federation" actually work (especially backed up with the threat of a genesis device)? Because right now, while Spock didn't lose his centuries-lasting game of chess, did he actually win it? Only time will tell.