Imperial Saga

Here. An Alternate Universe fantasy game with Steampunk and Magitek elements. Characters are citizens of a vast empire (not that kind), composed of a plethora of kingdoms -- many of whom don't like each other. Add into that a number of factions with their own ambitions, and you have a recipe for high tension, chock-full of political intrigue.

This game provides examples of:

 * Accidental Marriage
 * Alternate Universe
 * There's also AU within the AU, as someone pitched the idea of having a Grail War in Dagaria and a few people jumped on it. Amusingly, this game's version of Arturia Pendragon has absolutely nothing to do with the Grail War this time. Yet.
 * The list: Fate Testarossa as Saber (Master: Nanoha Takamachi), Idranel of Ulthwe as Lancer (Master: Indiana Jones), Signum as Archer (Master: Hayate Yagami), Luca Blight as Rider (Master: Lord Yuna, Lina Inverse as Caster (Master: Roy Mustang), Shiki Ryougi as Assassin (Master: Ishida Mitsunari), and Garviel Loken as Berserker (Master: Nero).
 * Angels Devils and Squid: There is a Heaven, a Hell, and a pit in the world crawling with Lovecraftian monstrosities and the undead. The latter is more or less the most relevant to day-to-day life.
 * Anthropomorphic Personification: Thanks to Mitsunari-Mun, there are now Faction-Tans for every faction currently in the game - they only exist OOC and are Just for Fun
 * They're also Moe Anthropomorphism, especially Rift-tan.
 * Apocalypse Maiden: Hayate, as per canon. This time,.
 * Arranged Marriage: One of the mechanics outlined in the rules. Players are permitted (and encouraged) to make use of it. The list thus far:
 * Roy Mustang and Cornelia li Britannia
 * Integra Hellsing and the Major (wedding occurred, was a disaster)
 * Athrun Zala and Euphemia li Britannia (wedding occurred, went off without a hitch)
 * Mitsunari Ishida and Sara Werec
 * A Storm Is Coming
 * Authority Equals Asskicking: Saber. King Bradley. Char Aznable. Need we go on?
 * Back From the Dead: Characters who are killed are sent to one of multiple afterlives, but they can return if they choose -- be it through diplomacy, manipulation, or force.
 * Colonel Badass: Roy Mustang and Jade Curtiss.
 * Color Coded for Your Convenience: Zeon has multiple characters associated with the color red, from Char Aznable, the Red Comet, to Cecil Harvey, commander of the Red Wings, to Athrun Zala, the Red Knight.
 * The Corruption: One of the risks of the Rift.
 * Cool Big Sis (Excellen)
 * Corrupt Church: The Church under Delacroix's reign - while many of the members are honest, The Pope solely seeks power and inquisitions are not uncommon.
 * Crystal Dragon Jesus: The Church is modeled after Christianity, and it's monotheistic, but it worships, amusingly enough, the Crystal King -- who resides in the Crystal Palace.
 * Dance Battler: Eleuseus,
 * Dead Serious: Though nobody really mourns Black Mage, nor does anyone expect he won't stick around, the events surrounding his death make it count anyway.
 * Deadpan Snarker: Xykon's reaction to the incident at Stratholme? "I really don't like that I just got totally outshone by a card."
 * Defrosting Ice Queen: Roy Mustang is trying to coax Cornelia li Britannia into becoming one of these. Time will tell whether or not he succeeds.
 * Eldritch Location: The Rift.
 * Everyone Is Bi: In Rome, anyway.
 * Evil Versus Evil: The two most militarily important kingdoms are both run by Omnicidal Maniacs. Who hate each other. The only things keeping Zeon and Amestris from engaging in a war of mutual extinction are the threat of the Rift, the Emperor's political power, and the fact that both King Bradley and Char Aznable have more complex plots than simply killing each other.
 * Expy - a mysterious, long-nosed old man gives your character a Tarot reading in a dream at some point after (or before) you join. Yes, this is supposed to sound familiar, even though the Tarot Card concept as used in the game is taken from a different game series entirely.
 * We also have characters filling similar roles for others' plots, such as Athrun Zala, who served under a Char Clone in canon, and serves under the man himself here.
 * Fantasy Counterpart Culture: Sawa for ancient Japan, Britain for... Well, obvious, and Rome... ditto.
 * Fantasy Kitchen Sink: The game takes elements from character's original canons and fits them into the backdrop; all that's required is that the element is cool.
 * The Federation: The empire is a monarchical version of this.
 * Fire and Brimstone Hell: Hell, natch.
 * It's good to note there are an (unknown) number of afterlives possible - how exactly it works is kept very mysterious. Hell does, however, have Horny Devils.
 * Flat Earth Atheist: With the prevalence of multiple gods and their making appearances to mortals, any atheist in the game automatically falls into this trope.
 * For the Evulz: Team Evil.
 * Four Star Badass: Cornelia li Britannia.
 * Ghost Town: Stratholme, now.
 * Government Conspiracy: Expected when one of the kingdoms is Amestris.
 * Green Rocks: The crystals.
 * Heroic Bastard: Thomas - due to the late king hiding his existence, he is also the Unexpected Successor since his legitimate brother had ran off.
 * Hot Blooded (Mitsunari Ishida)
 * Hypercompetent Sidekick: Light Yagami is this to Mitsunari Ishida, generally being more aware of what's going on politically and reigning in Mitsunari's temper.
 * I Was Just Joking: How Mitsunari ended up in an Arranged Marriage...
 * Killed Off for Real: This, too, can happen, if a dead character lacks the ability to escape the afterlife and/or simply chooses not to.
 * Klingon Promotion: Expected and encouraged.
 * Lady and Knight: Nero and Garviel Loken are Bright Lady and White Knight, Rao and Ky Kiske have a similar dynamic, also a Bright Lady and White Knight example.
 * Lady of War: Cornelia li Britannia, Saber, Integra Hellsing, and Signum.
 * Magitek
 * Mad Scientist (Dist, also Gadgeteer Genius)
 * Majorly Awesome: Jin Kisaragi, Ky Kiske, Souji Okita, and (obviously) The Major.
 * Mean Character Nice Actor: With the number of villains and Jerkasses in the game, this is inevitable.
 * Mistaken for Servant: Shiki/Assassin. She is, of course, but...
 * Mistaken for Cheating: After Mitsunari tries to clear up the above misunderstanding.
 * Names the Same: For the second AU game in a row, two players couldn't resist making Light Yagami and Hayate Yagami siblings.
 * My Sister Is Off Limits: A variation. Cornelia is so protective of her sister that she disapproves of her having a relationship at all. Needless to say, she utterly disapproves of Euphemia's engagement (now marriage) to Athrun. It's a variation because Cornelia and Athrun barely even know each other.
 * Mythology Gag: Plenty.
 * Indiana being part of the Grail War
 * Athrun working for the original Char
 * Additionally, Athrun being engaged to a peace-loving, pink-haired princess -- though this time, he actually marries her.
 * Non Player Character: Emperor Terenas Menethil.
 * Obviously Evil (Xykon, Black Mage)
 * Our Elves Are Different: Elves live in the Fairy Realm. They're rumored to live in a Crystal Spires and Togas society and to be immortal.
 * Rain of Blood: When Arthas uses the Tower to kill his own army at Stratholme.
 * Running Gag: Narwhals
 * Black Mage getting killed in every combat log he appears in.
 * Evil characters calling Sara a slut.
 * Sacrificial Lamb: The majority of the population of Stratholme. Black Mage, too, but he came Back From the Dead.
 * Emperor Terenas Menethil also counts.
 * Shades of Conflict: The first four major kingdoms in the game range from the typical white knights (Arturia's Britain) to the well-intentioned but potentially underhanded (Mitsunari's Sawa) to those with a veneer of nobility over genocidal tendencies (Char's Zeon) to people who employ Nazi Vampires as regular retainers and attack Hidden Elf Villages For the Evulz - but at least the Rift is contained and the trains run on time (Bradley's Amestris) to the openly honest conflict neutral Nameless States.
 * Shipper On Deck:
 * Euphemia ships Roy/Cornelia, much to her sister's chagrin. King Bradley does, too, but.
 * Kira seems to ship Athrun/Euphemia, despite his own crush on Euphie.
 * Shout Out: These happen sometimes, usually to the characters' original canons. For example, Athrun Zala being sent to rescue his fiancée, and said fiancée -- Euphemia li Britannia -- jumping out a window to reach him.
 * Spiritual Successor: To Romance Of The Infinite Kingdoms. It's also been called the second TST.
 * Start of Darkness: Presently happening to Arthas Menethil, with Xykon nicely filling in for Mal'Ganis.
 * Stealth Pun: Sara being Char's younger sister is not only an expy joke, it also makes her A Little Princess.
 * Steampunk
 * Tarot Motifs: Each character finds themselves in the possession of three magical tarot cards, each of a different Major Arcana. These have various effects.
 * They Killed Kenny: A Running Gag for Black Mage.
 * Throwaway Country: Stratholme is the first throwaway town, and considering the story so far, it probably won't be the last, either.
 * Troll: This seems to be the primary use of Destiny Crystals by Card Carrying Villains like Xykon and Black Mage.
 * Mitsunari seems to be a favorite trolling target, and even his subordinates get on the act!
 * Warrior Heaven: The Halls of Valor.
 * World of Badass: The game description even implies it!
 * Wutai: Sawa is where most of the Pre-Meiji Era Japanese characters have been gathered.
 * X Meets Y: The kingdoms that don't fall into Fantasy Counterpart Culture fall into this.
 * Amestris: Amestris meets Britannia meets the NOL.
 * Zeon: Neo-Zeon meets Baron meets the Gestahlian Empire meets ZAFT.
 * You Kill It You Bought It: It's possible to happen if a character is particularly lucky -- or unlucky -- when dealing with their superiors.