Ghosts of Onyx

Ghosts of Onyx is the fourth Halo novel, written by Eric Nylund. It tells the story of the Spartan-III super soldiers, the successors of the Spartan-II program, and their training on the classified planet Onyx, which is also where the story culminates.

Tropes used in Ghosts of Onyx include:

All of Them:

"We've got incoming," Fred's static-filled voice crackled over the COM. "Sentinels."
"How many?"
"Sir, all of them."

Badass Boast: Vice Admiral Whitcomb delivers one (posthumously) through a recording in a NOVA Bomb:

"This is the prototype NOVA Bomb, nine fusion warheads encased in lithium triteride armor. When detonated, it compresses its fissionable material to neutron-star density, boosting the thermonuclear yield a hundredfold. I am Vice Admiral Danforth Whitcomb, temporarily in command of the UNSC military base Reach. To the Covenant uglies that might be listening, you have a few seconds to pray to your damned heathen gods. You all have a nice day in hell..."

Dyson Sphere: Onyx turns out to house one.
Earthshattering Kaboom: Onyx isn't really a planet in the traditional sense, but it does disintegrate into billions of Sentinels.
Forbidden Zone: Zone 67.
Heroic BSOD: The loss of almost all of Beta Company on Pegasi Delta causes Lucy to have one, resulting in her not speaking ever again. Or, and least, not for many years.
Hope Spot / Diabolus Ex Machina: Admiral Patterson is down to one carrier and three destroyers, facing two damaged Covenant destroyers. One is taken out, leaving a single Covenant ship utterly defenseless. And then a Covenant fleet 32 ships strong comes out of slipspace between the lone destroyer and the four UNSC ships, and promptly annihilates the human vessels.
Laser Guided Tykebomb: Unlike their predecessors, the Spartan-III super soldiers were made to be expendable.
Made of Iron: The fact that Will was even able to take a few steps before keeling over and dying after taking an unshielded blast to the midsection point-blank from a Hunter's cannon is testament to his toughness.
Pre-Mortem One-Liner / See You in Hell:

"One last fight, demon. You will die and we shall reopen the silver path."
"Die?" Kurt laughed. "Didn't you know?" he told the Elite. "… Spartans never die."

Rouge Angles of Satin: The first edition of the book was full of glaring typos, such as the Spartans sneaking past Grunt "salves" and trying to escape Covenant "persuaders."
Sacrificial Lion: Kurt and Will.
Taking You with Me: Kurt detonates nuclear warheads in Onyx's core room, taking all Covenant forces on the planet with him.
The Speechless: Lucy apparently loses her ability to speak as a result of being traumatized from the outcome of Operation TORPEDO.
Trapped in Another World: In the end, the main characters get trapped in a Shield World inside Onyx, with no apparent means to return home.
You Shall Not Pass: Kurt holds off Covenant forces long enough for the Slipspace portal on Onyx to close thus saving the other Spartans and Dr. Halsey.