Mirror Duet

"Every dream you've ever had, and every dream yet to come, exists somewhere in the Kingdoms of the Void. Every nightmare, too. Because there has to be balance - it's the rules."

Two books written by Catherine Webb: Mirror Dreams and Mirror Wakes, set in the land of Dreams and Nightmare.

Tropes used in Mirror Duet include:

Adventures in Coma Land: The entire damn plot of both books.
All Just a Dream: Well, not just a dream.
Ascended to A Higher Plane of Existence: Renna and Miriam.
Badass Boast:

"Let's see what a hundred years have done for your memories. Who made the elementals' network?"
The cry was taken up only by a few older agents, but they said it with a passion and conviction the carried across the room. "Kite!"
"Who prevented the Seven-Kingdom revolt?"
"Kite!" More voices now, as more memories clicked.
"Who introduced he canteen in the lower halls?"
"Kite!"
"Whose soup gave everyone food poisoning for a week?"
"Kite!" I doubt there wasn't a single voice which didn't yell out.
"And who's standing on stage now, saying that you," I pointed a dramatic finger at Jehirer, "are no good at the job?"
The cry shook the ceiling and echoed across the hall.
"Kite! Kite! Kite! Kite!"

Balance Between Good and Evil: Without the balance between dreams and nightmare, the people of Earth will destroy themselves and there will be no more Void, no more dreams, no more nightmare.
- In a strange way, between the Void and Earth, too.

Dreamers affect the physical form of our world, we affect the mental shape of theirs. Who now the greater power holds?

Bastard Bastard: Xavian, the Firepoint and Sunpoint crossbreed.
The Big Board: The Silverhand Consortium has one, mapping kingdoms aligned to dreams and nightmare and neutral kingdoms as well.
Breaking the Fourth Wall: Our mage in white addresses us all the time.

Laenan Kite (after a long and flowery bit of exposition): Don't you dare fall asleep on me yet!
Laenan Kite: Sorry guys, dreamers are never in the kingdom long enough - the longest you see and dreamer for is ten or so hours - to set up shop. So, you wanna job? You gotta stick to your own dull little planet.
Laenan Kite: Are you surprised, dreamer? Are you surprised that I could be so much less of a man within? Do not be.
Laenan Kite: Noses always itch at the worst possible time, dear dreamer.

Combat Pragmatist: Most mages don't think of bringing guns and knives to a fight. Kite also applies the laws of physics in his magic, so when his opponent makes a giant flashy fireball he simply adjusts the heat flow and kicks them in the shins.
Dangerously Genre Savvy: Kite, only you would think of turning shit into acid.
- Scry-blocks.
Dream Apocalypse: As Kite points out, if someone is a dream, what happens when their dreamer dies? Creates a Fridge Logic moment when you realise that Renna is immortal and Kite is her dream.
Dream Land: Our setting
Dream Spying: On our lord of dreams, with Earth as the dream, no less.
Dreaming the Truth
Dreaming of Things to Come: Lots of dream tropes, eh?
Dream Weaver: Mages can create worlds that respond to their mind - dreams or nightmares. However it takes a lot of resources, time and paperwork galore.
Evil Gloating: You should have really known better, Serein.
First-Person Smartass
Fisher King: The kingdoms of the Void.
Hannibal Lecture: Oh so often. Having dealt with so many lords of nightmare Kite usually has some pretty snappy comebacks, too. YMMV on if they are actually justifications, or just make Kite feel better. Lampshaded:

Laenan Kite: Anger at Renna for using me, anger at Miriam for refusing to see the truth, anger that, in their own strange ways, all of them were right. Even Xavian, in a way. There had been to much war.

Heroic Bastard: Laenan, Saenia, Talsin, in a sense.
Ironic Echo: Courtesy of Renna, in the form of Serein in Mirror Wakes.
I Was Having Such a Nice Dream: If Kite had just dreamt of Earth a little longer, thing would have been a lot simpler for him in Mirror Dreams
Kirk Summation: Kite.
Land Down Under: Renna is in a hospital in Sydney in Mirror Dreams
Lineage Comes From the Father: Averted. Who knows where Saenia and Laenan get their magical gifts from, but it ain't their father.
My God, What Have I Done? Quoted almost verbatim when Saenia makes Laenan realise just where his ambitions led him.
Names to Run Away From Really Fast: Our lord Kite, Warden of Stormpoint, one-time Master of the Mage's Library and Councillor to Haven.

Laenan Kite: Too many titles have always worried me, and that sentence was packed full of them. I've had enough titles in my time to fill a small book, and I know they bring nothing but trouble.

Never a Self-Made Woman: Played with. While Laenan is the more famous of the magically gifted siblings, Saenia is definitely more powerful, and the elder. As Laenan puts it: "If those fools in Haven sit and call me an archmage, then Saenia is way off the scale".
Overlord, Jr.: Serein.
Shut UP, Hannibal: Kite, you learn that after 600 years of fighting nightmare.
Shut Up, Kirk: Just about everyone to Kite, especially in Mirror Wakes.
Reality Warper: Dreamers.
Retired Badass: Laenan, at the start of Mirror Dreams. It's more of a hundred year sulk over getting betrayed by the Prince of Dreams and nearly getting executed for high treason.
Sue Donym: Lenian Kiret, guess who?
Somebody Else's Problem: The spells: Who, Me?, Not my Concern
Talking Is a Free Action: Even for all of Laenan's claims to Genre Savvy and Why Don't Ya Just Shoot Him moments, Webb seems to have a weakness for drama. Characters often make long speeches, only occasionally with any preparation. For example, Kite (admittedly not on the right side of sanity right then) took the time to yell, "You will die, Serein! You and all of yours!" when he was exhausted and jumping out of a tower into three dragons he just shot, in a newly conquered realm of nightmare.
Up the Real Rabbit Hole
Visions of Another Self: Laenan Kite and his Earth counterpart: David Kiteler

Laenan Kite: In fact, he looked bloody well just like me. And I'm not kidding. He had the same blue eyes, the dark hair, the same ordinary nose, chin, face . . .

What Happened to the Mouse?: Why didn't Windsight even get a mention in Mirror Wakes?
- He's probably upset with Kite after he got his daughter killed on a mission to Firepoint and making his Ward Ascended To A Higher Plane Of Existence Disappear to retake Haven quickly after he specifically warned him to keep the hell away form her.
You Killed My Father: Serein.
Your Mind Makes It Real: Dreamers.