There is enough room for 1 stack of every item, so it is theoretically possible to break by getting 99+1 of multiple types of items, but unlikely
Badass Adorable: A dragon that has control over time? A beast that can expand space? A creature from a world separate from ours with control over antimatter? The creator of the universe? NO PROBLEM!
Took a Level in Badass: As a norm in every Pokémon game. Even capturing Dragons of space, time, and antimatter, and even GOD (aka Arceus).
Hair Color Dissonance: There's confusion about their hair color. Sugimori drew it a navy blue (or arguably black with blue hints) type color in their main artwork, but everything else except for Pokémon Special has them with a lighter hue.
Love Interest: They play a subtle version of this role with each other.
Mini Dress Of Power: Dawn. There is some minor confusion about whether it's really a dress or just a coat, though many would be more comfortable with the dress idea.
Judging by the anime, she's wearing a minidress in Diamond and Pearl and a coat over that minidress that happens to be the exact same shape and size in Platinum.
Missing Mom: As an NPC, though fanon has the female scientist in Rowan's lab as their mom.
Lucas's hair and eye color matches Johanna as well, albeit not the same shade.
Theme Naming: Both their American names have to do with light- Lucas comes from the Latin "lux," which means "light," and Dawn comes from the time of day the sun rises. Works in Japanese too - the "kou" in Kouki and "hikari" can refer to the character for "light".
Character Development: As the story goes on, he becomes more patient and less hasty. He also becomes better at creating strategies and learning from his losses.
Crash into Hello: Your rival's normal way of greeting you. Lampshaded during one of your mid-game encounters with him, where he doesn't crash into you and gleefully points this out, asking if you were surprised.
"Thud!!"
Fighting Your Friend: Basically, what you do with him. It defines your relationship.
Foreshadowing: When talked to, she mentions "the Pokémon among flowers." This is referring to Shaymin, a Pokémon that wasn't available in a legit way until a while after Diamond and Pearl's release.
Fragile Speedster: Her team specializes in the Speed stat. ((Many of them aren't that fragile, but quickness is always their first priority.)
Does Not Like Shoes: In Platinum, you encounter her walking all the way to Snowpoint without shoes or any appropriate clothing. This is apparently related to her training.
Faux Action Girl: Not that she's not a good fighter, but her reputation of being tough seems overblown by the time you battle her.
Name's the Same: She and a Kimono Girl from Gold and Silver had the same Japanese name. The Kimono Girl's name changed to Komomo in the remakes, possibly because Maylene makes a cameo.
In a roundabout way, there's also the fact that her German name is Hilda....
Large Ham: While most Gym Leaders are relatively subdued individuals who try to demonstrate the versatility of their element of choice, Wake's a Hot Blooded masked wrestler who insists on always adding "Crasher" before his name. In Platinum, if you refuse to fight him at the Top Trainer Cafe, he will sing his theme song. And on the TV from time to time, it will describe him fighting wrestling matches. He even shows up a few times in HeartGold and SoulSilver, first giving you the three Sinnoh starter masks (which he appears to force on you, commending your love of masks), and later on the bridge to the Safari Zone, where he goes off on a rant about how cool waterfalls are.
Meaningful Name: A wake is also the set of triangular waves left by something traveling through water (a boat, etc.). Also sounds similar to "crashing wave".
Shirtless Scene: He never even wears a shirt, even when traveling away from home to Johto as seen in HeartGold and SoulSilver.
"Candice is on fire! I'm blazing hot! Hot enough to melt Ice-type Pokémon! I need a battle to cool me down! OK! I'll show you how good Candice can be! I mean, how good my Pokémon can be! Awww! That's it! I'm going to train so I can throw a Focus Punch myself!"
Volkner (Denzi)
Sunyshore Gym Leader—The Shining, Shocking Star!
The Ace: Though a bit character, he has elements of this. He hadn't had a good match in a long time before you showed up, to the point where he was about ready to resign as gym leader and take on the Elite Four. On top of this, he got so fed up in his boredom that he took on an extremely outlandish project to remodel his gym and ended up blacking out all of Sunyshore City. Where most of the walking space is made out of solar panels.
Deadpan Snarker: He acts like this to Flint, if the chat at the player's villa is any indication:
Volkner: Flint's fascination with fire-types comes from his name. Someone once told him a flint was used to start a fire, and that was it.
Stellar Name: Team Galactic's admins are named after planets, their leader's name means "sun", and Platinum's newly added member is named from one of Pluto's moons. (Or just named from Pluto in Japanese)
Team Galactic's leader. He despises emotions, feeling that they are "weak and incomplete", and wishes to purge them from the universe. To do that, he intends to destroy the universe with the power of Dialga and/or Palkia, and then remake it with himself as God. Needless to say, he's batshit insane. You need to stop him. Never mind that you're eleven.
Abusive Parents: It's implied that his parents were at the very least severely emotionally neglectful, and the situation was so bad that his grandfather considered taking him away from them. He didn't go through with it though, and he's regretted that decision ever since.
A God Am I: More pronounced in Diamond and Pearl than in Platinum (In the latter game, he fixates more on the new universe itself rather than the fact that he'll be a god ruling over it.)
Badass Bookworm: Just listen to him lecture you about genes. He's studied a lot.
Bad Boss: Made explicitely clear in Platinum. Granted, it only really kicks in as part of his overall plan, since everyone but him would die anyway; before then, his primary form of punishing his agents was to take away their Pokémon.
Chekhov's Gunman: In Diamond and Pearl, he is first seen when you first visit Mt. Coronet, but you don't find out who he actually is until the end of Team Galactic's Hideout. In Platinum, he's introduced even earlier (in the first twenty minutes of the game, no less), but you also find out who he is earlier.
Cry For The Devil: His backstory. Especially since you hear it from someone who had a chance to help him when he needed it, but... didn't, and now it's too late.
Dark Messiah: Seems to see himself this way, at least in Platinum.
Death Glare: Possibly, his default expression- certainly his most famous.
Early-Bird Cameo: In Platinum, his very first appearance is when you and your rival first come to Lake Verity soon after obtaining your starters - he monologues (though somewhat intended for Mesprit to hear) about how he'll capture the Lake Trio as part of his plans
It's All About Me: And NOT in the standard way like Charon. He genuinely sees himself as alturistic, but in Platinum he reveals that he sees Team Galactic as tools for achieving his ends, that only he will claim power as a god, and "making the world a better place" will depend only on what he views as being better for everyone, which turns out to be a world devoid of spirit.
Karma Houdini: Cyrus is the only Big Bad in the main series who doesn't reform or otherwise get punished for his actions. At least in Platinum, he suffers a brief raging breakdown due to his plan being foiled in a way that he can't repeat it the same way again; in Diamond and Pearl, he just shrugs his defeat off and vows to start anew. And even in Platinum, while he is last left in the Distortion World, it's not like he's trapped there: he's clearly staying there by choice in order to unlock more of it's secrets.
Knight Templar: He believes his terrible, destructive plan to be in the entire world's best interest.
Kubrick Stare: He gives you a pretty good one in the intro of Platinum.
Light is Not Good: If you consider that he's named after the sun....
Meaningful Name: His Japanese name, Akagi, can be read as "red future." His American name, Cyrus, comes from the Persian "Kuros," meaning "sun." This ties into Galactic's Stellar Name pattern as well as the fact that the Commanders "revolve" around him.
Misanthrope Supreme: Prefers the company of machines to humans or even Pokemon.
Morality Pet: One of his Pokémon is a Crobat, which only evolves if it really, really loves its owner.
Name's the Same: Shares his name with a random Ranger in the Battle Tower.
Nietzsche Wannabe: To him, "useless emotions and sentimentality are products of the weak and incomplete human heart."
Not So Stoic/Sanity Slippage: Very much so in Platinum, once you get him inside the Distortion World. Just before battling Giratina, you battle him, and here is what he says:
"Why should I run and hide from the world and have to wait quietly? My aim is to rid our world of the vague and incomplete thing we call spirit. By freeing ourselves of that, our world can be made complete. That is my justice! No one can interfere! I won't lose! Not to that shadowy Pokémon! Not in any worthless world!"
And then after you defeat him and capture/defeat Giratina:
"That Pokémon... That shadowy Pokémon was captured/defeated?! Your doing so means that this irrational world will remain in existence! Does that make it impossible for me to create a new world? Even if I made new Red Chains, the new world can't be made! Why?! What compels you to protect the two worlds? Is spirit, a vague and incomplete thing, so important to you?! Silence! Enough of your blathering! That's how you justify spirit as something worthwhile?! That is merely humans hoping, deluding themselves that they are happy and safe! The emotions broiling inside me... Rage, hatred, frustration... These ugly emotions arise because of my own incomplete spirit!"
"...Enough. We will never see eye to eye. This, I promise you. I will break the secrets of the world. With that knowledge, I will create my own complete and perfect world. One day, you will awaken to a world of my creation. A world without spirit."
Omnicidal Maniac: Hoo boy. He regards the world as incomplete, so he plans to destroy it?
Destroy it to build it again, so basically it was just in the way.
Translation Correction: In the Japanese version, Cyrus's name means "red castle/tree/future", breaking the Theme Naming of his team. Every translation except the Korean version gives him a name meaning sun or naming him after a sun god.
Troubled, but Cute: More troubled than cute, but still fits, at least in Platinum.
Younger than They Look: He's 27. Possibly justified by the extreme degree of overwork and stress he's put himself through since he was a child, as his grandfather explains.
Dragon-in-Chief: Presumably takes on this role whenever Cyrus in unavailable and eventually takes charge of Team Galactic.
Heel Face Turn: After Cyrus's defeat, he takes over Team Galactic and turns it into a legitimate organization dedicated to finding new energy sources for the planet's well-being.
Locked Out of the Loop: In Diamond and Pearl, it seems. He's much more aware of Cyrus's goals in Platinum, however.
Took a Level in Badass: Though he's the only major Galactic member not to gain an extra battle with the player in Platinum (barring Charon), his team is still a little stronger than before.
Well-Intentioned Extremist: Not quite as extreme as Cyrus, but he does still initially want to improve the world by destroying and recreating it. The difference comes when he discovers Cyrus wants all emotion and spirit gone, something Saturn doesn't want for the world.
Curtains Match The Pokémon: As well as having purple eyes and hair, her hairstyle resembles Medicham's topknot. Only problem is, no one in Team Galactic has a Medicham.
Dual Boss: In all three games, for her 2nd battle with you she teams up with Mars. Your rival joins up with you, which evens out the odds.
Kick the Dog: How she treats your rival after defeating him.
The Dog Bites Back: When he and you team up against her and Mars, defeating them quite handily.
Recurring Boss: Though not as much as Mars, she does quite quite a few battles out of you (two in Diamond and Pearl, three in Platinum). In all games, the 2rd battle is a Dual Boss situation (see above).
Dual Boss: In all three games, for her third battle with you she teams up with Jupiter. Your rival joins up with you, evenning out the odds.
Evil Red Head: Though probably the least evil of the Galactic commanders, as she's always the most reasonable with you whenever you meet, even though a little tempermental.
Hair-Trigger Temper: She's easily prone to anger, and even has to talk to herself in order to calm herself down.
Mad Love: Implied to have a crush on Cyrus, and honestly thinks he's doing good. Though most think she'd probably be better off with Saturn, what with the aforementioned Curtains Match the Window example.
Recurring Boss: Mars gets the most mileage out of battling you of all the Galactice Commanders (three times in Diamond and Pearl, four in Platinum). In all games, the 3rd battle is a Dual Boss situation (see above).
Well-Intentioned Extremist: Says in her debut that she really wants to improve the world and is saddened that other people don't seem to understand Team Galactic's cause.
Even Evil Has Loved Ones: Charon's probably one of the least sympathetic characters in the game, what with his lack of a Freudian Excuse or 'noble' goals, but that doesn't stop him from writing about how much he loves his Rotom.
Meaningful Name: Probably unintentional, but his American name is from Pluto's moon, notably the only heavenly body used for a Commander's name that doesn't directly revolve around the sun. Charon doesn't "revolve" around Cyrus like Mars, Jupiter, and Saturn.
Additionally, as he's shown to be the most heartless member of the team (his goals and plans are less dangerous than Cyrus's, but with no delusions of altruism to his goal, it's for less of a "meaningful" reason), consider that he's named after either a death god or the ferryman of the underworld...and how many would have died if he'd been able to control Heatran in his quest for money and self-aggrandizement.
Morality Pet: Rotom. At the very least, it used to be his friend, but sadly, he seems to use it for nothing but experiments these days. He might have even abandoned it at the old chateau once it had no more use.
Only in It for the Money: Unlike everyone else in Team Galactic, he's not looking to create a new world. It's all about money, power, and glory for him. There are even hints that he used to be with Team Rocket, where that mindset is the norm.
Name's the Same: Has nothing to do with Brock's father from the anime.
Playing with Fire: He apparently chose to train them solely because of his name. This was changed from the Japanese version, where his favorite move is Overheat because it matches his name (Oobaahiito and Ooba).
Name's the Same: Along with Aaron, he shares a name with one of the protagonists of the English release of Lunar Knights.
Psychic Powers: At least with his Pokémon, because it isn't quite clear whether Lucian has them himself like most Psychic-type specialists (in contrast to how Sabrina expected Red to face her in Generation I, Lucian finishing a book as soon as the player walks into his room is merely stated to be good timing). At the very least, he's stated by an NPC to have a fondness for books on ESP, as well as books in general considering his frequenting the Canalave Library.
Purple Eyes: Falls squarely into the badass category, being the final Elite Four member.
Ascended Extra: Since Gen III, the series has gone way off the Non-Linear Sequel scale - Characters from previous "generations" are assumed to be far away, and barring some stray cameos here and there, you're lucky to even hear about them. Cynthia has been in every game since her introduction, including Updated Rereleases of older games.
Brilliant, but Lazy: Her place is a jumbled mess of research papers and she'd rather leave saving the world to underqualified preteens. She's also by far the most powerful trainer in the region (not counting that part later in the game where the player character inevitably undertakes a marathon of Level Grinding and achieves godhood).
Cool Big Sis: She's an older sister, and she acts like this to you.
Graceful Loser: Up to the battle, she does the usual "I see the strength in your heart and accept the challenge" bit that nearly all powerful trainers in the series seem obligated to recite by contract, but as the battle progresses, she gradually stops bothering, and her response when you beat her is basically a "Yay for you!".
Grey Eyes: Fits the mentor part of the first type, minus the dying.
Leitmotif: Two of them; one during the dialog before battle and the other during battles. She keeps both across generations, promoting them from normal Final Boss themes to this. Her introductory theme can be heard any time in Platinum if one's villa has a piano.
Woman in Black: Although the anime makes it more of a slightly dark grey.
Frontier Brains
Elite Trainers who each preside over a Battle Frontier Facility who award prints to those who show true skill and battle prowess. They also appear in HeartGold and SoulSilver in the same roles.
Generation Xerox: His son takes a lot after him, and there's the fact that he and the player's father became trainers the exact same way the player and Barry did.
Castle Valet Darach and Caitlin (Kokuran and Cattleya)
Berserk Button: Much like Sabrina, Caitlin has psychic powers of her own; she is the real Frontier Brain, but you don't battle her because she can't control her powers, which go berserk every time she loses. She gets better in Pokémon Black and White and becomes a member of the Elite Four.
Bodyguard Crush: A minor character in the Battle Castle mentions that Darach has feelings for Caitlin, but doesn't show it.
Fighting Your Friend: Arguably fighting against Darach - he aids you in the Castle immensely until you reach the end of the third consecutive set of battles, in which you must fight him.
