BattleTech: Crimson Night (The Rogue Academy Trilogy, Book Three‪)‬

A WORLD IN FLAMES…
 
Emporia has been bombed into disease-ridden ruins, and the planet's remaining forces have been scattered. Jasper and Nadine Roux are among the few surviving cadets from the Ritza MechWarrior Academy. They and their war-torn peers are all that stands in the way of Tai-sa Takeji Yoshizawa's plan to conquer their homeworld.
 
Tai-sa Yoshizawa battles dissension within the ranks of his most trusted advisors as he struggles to complete his conquest. Desperate to solidify his hold on Emporia, the rogue Draconis Combine colonel will use every option at his command—including capturing the last surviving heir of Emporia and claiming him as his ward, then ruling the planet through him.
 
It is a race to see who can reach the Ritza family first. With Nadine coordinating the survivors' evacuation from space, and Jasper on the ground fighting his way across a shattered world, everything rests on what happens when Emporian and enemy forces collide in an epic battle and the winner takes all in this explosive conclusion to the Rogue Academy trilogy.