Big Ego, Hidden Depths: Many episodes (particularly ones where the Dragons have strained relations) suggest that Omi fears being alone and believes that if he is perfect, he will be surrounded by adulating friends and admirers.
Honor Before Reason: Omi is completely devoted to the way of the Xiaolin monks. This means that he often does incredibly stupid things, including playing into the villains' hands, because he gave his word as a Xiaolin warrior. Interestingly, this seldom overlaps with Chronic Hero Syndrome, as Omi's complete devotion to his duties as a monk can make him hesitant to help people not directly connected to said duties (such as with the old woman in "The Bird of Paradise").
Innocent Bigot: To Kimiko. His sexism stems much more from his sheltered upbringing and lack of knowledge than anything else.
Insufferable Genius: For all his bragging, Omi is indeed a talented martial artist with more training than the other monks.
Meaningful Name: Though more than likely an unintentional Bilingual Bonus, Omi is the Yoruba word for "water". Considering it's a Chinese character made by a Chinese creator, it's strange he would have a Nigerian word for a name.
Big Ego, Hidden Depths: Rai becomes angry whenever he feels helpless or inadequate, as shown during the events leading to his betrayal. It's straight-up stated in "Dream Stalker" that his lazy, jerk-ish attitude results from his fear of not being good enough and letting others down.
Chronic Hero Syndrome: Despite his jerkish tendencies, Raimundo is always the first to put aside the task at hand to help someone in need, regardless of personal risk. However, this seldom overlaps with Honor Before Reason, which is generally reserved for Omi.
Cool Sword/Fighting with Chucks: Both the Sword of the Storm/Lucida and the Blade of the Nebula are swords that can manipulate wind and weather (but can't actually slice anything). The Blade of the Nebula can turn into nunchaku for greater control and versatility in wind manipulation.
Jerk with a Heart of Gold: The heart of gold part is made very obvious in episode 9. Omi gets separated from the rest of the Xiaolin Dragons, and when they find him again, Raimundo pulls him up and hugs him profusely while expressing his heartfelt worry and relief, complete with a parodying playing of the violin.
Raimundo: "You're alive! Don't you ever scare us like that again, we were so worried and I...what? I was worried."
Daddy's Girl: Kimiko's obviously very close to her videogame tycoon father, Toshiro Tohomiko.
Kimiko's presumably an only child, as no other Tohomiko chidren are ever seen or mentioned. Also, Kimiko's mother is never seen or mentioned, so it can be assumed Toshiro's either divorced, a widower, or he and Kimiko's mother were never married.
Funny Foreigner: He's an Asian boy who was raised in Europe. Exactly which country is not known, but he has six names that are Slavic, Italian, German, and/or French, and he's fluent in each of those languages.
The legendary Xiaolin Dragon who defeated Wuya and hid the Shen Gong Wu 1500 years ago. According to the ancient Scroll of the Shen Gong Wu, Dashi was the first and most powerful of all Xiaolin Dragons.
Batman Gambit: He acts like a Drill Sergeant Nasty to make Hannibal Roy Bean sway Raimundo to his side. After Raimundo pummels Omi in a Xiaolin Showdown, Guan makes Hannibal bet the Treasure of the Blind Swordsman against all their Shen Gong Wu, and Raimundo takes a dive. Thus, the monks get back the Treasure of the Blind Swordsman, which had given Hannibal a huge advantage.
Big Damn Heroes: When he appears to defeat Chase Young in his debut episode.
Big Good: Shared with Master Fung. Although he doesn't appear as much as Fung, he is the most powerful good guy, able to fight equally with Big Bad Chase Young and all his efforts are in direct opposition to the seasonal Big Bad.
Ambiguously Bi: Jack flirts with girls throughout the series (Kimiko, Jessie, Katnappe etc) while developing a fanboy crush on Chase Young (complete with adoring gazes through heart-shaped eyes, repeated attempts to hug and paw at him, and whiny jealous sulks whenever Chase rejects him). But also created an army of cheerleaders robots and enjoyed kissing one. Oh, and in the evil future where he takes over? He apparently has Chase Young constantly being tied up in nothing but his underwear, with butter being slathered on his abdomen, while Wuya is suspended from a wall in a cheerleader outfit. It's evident Jack Spicer swings both ways.
Badass Normal: His surprising skill at winter sports like skating and snowboarding and his fast reflexes, not to mention his flashes of brilliance. Also, there's the Bad Future where he takes over the world and defeats everyone. Yes, even Chase Young.
Badass on Paper: Despite being the laughing stock of the Heylin side he still has a fairly impressive bad guy Rapsheet.
Expository Hairstyle Change: When the effects of the Ying or Yang Yo-Yo switch him to good, his hair is combed and neat, but what is more interesting is its change to a more natural shade of red (i.e., orange) rather than its usual bright, crayon-like red.
Redemption Promotion: The times when Jack fights for the side of good are definitely times when he's much more competent. Notable examples are defeating Wuya's rock monsters with his robots (when the monks could not), having the foresight to use the Reversing Mirror on Katnappe when she invaded the temple, and the Sphere of Yun to trap the Chi Creature when it attacked.
Troubling Unchildlike Behavior: As a kid, he wanted Knife throwing lessons, but his mother took him for figure skating lessons, he invented a robot out of her juicer as a result. As a teen, he aims for world domination with his army of Jack Bots at his command...and yet he also uses winter sports as a Surprise Skill.
Villainous Crush: It's hinted that he may have a crush for Kimiko, but it's also possible that he only flirts with her to get her guard down.
Weapon of Choice: Among the Wu, the Monkey Staff seems to be his preference. He did keep it for himself when he traded the rest of his collection for robot parts.
We Want Our Jerk Back: The reaction of the Xiaolin Monks whenever he turns good via the Ying Yang World, because Good!Jack Tastes Like Diabetes so much that they like him even less than they do when he's normal.
Irony: It's been claimed by several characters (and proven once or twice) that she is a backstabber, and not to be trusted. The irony is, the one person she never even considered betraying is the one who betrayed her, and saved the world.
Took a Level in Badass: Initially borders on Harmless Villain, but when she gets her body back, she becomes far more of a threat. Even when Chase Young weakens her, she's still able to defeat the Monks more than once.
Too Powerful to Live: She's only been at full power once during the main series, and when she is, she easily takes over the world and is stopped by Dashi's puzzle box.
Invincible Villain: During the 2nd season when he took over as the Big Bad, regardless of what he did, he would defeat the Xiaolin Dragons if they tried fighting him, and almost nothing ever slowed his schemes down. Averted by the 3rd season and Chronicles when he does suffer defeats.
Necromancer: A one-time occurance when he raises a giant undead snake with wings to fight the monks.
Noble Demon: Chase is a ruthless half-dragon Heylin Warrior who won't hesitate to turn Omi to the Dark Side or seriously injure Jack Spicer (at the very least, considering he once tossed said "Boy Genius" off a dangerously high cliff and threw a dangerously large boulder at him in another episode), but you can bet your life and college savings that when he makes a promise, he'll keep it.
Extreme Omnivore: Her usual diet is insects. She also destroys one of Jack's spy cameras by snatching it up with her tongue and chomping down on it, and it doesn't look like all the pieces fall to the ground.
I Have Many Names: She calls herself the "Mighty Shadow" without any indication that's her real name. Ping Pong calls her "La femme brune" (the dark-haired girl) and "La grand ombre" (the big shadow).
A girl who met Jack Spicer at one of his parents' parties. After Jack failed in acquiring the Golden Tiger Claws, she joined him and Wuya on the Heylin side. She shows her affinity for cats by dressing up in a costume that consists of a form-fitting catsuit with heeled boots, a head cover, and cat ears.
Chronic Backstabbing Disorder: In her debut episode she takes the Golden Tiger Claws for herself rather then give them to Jack and Wuya. In a later episode, she likewise abandons Wuya when the mission became too annoying for her. Needless to say, she doesn't work well with others.
It's All About Me: Unlike most of the other villains, she has little to no interest in world domination. Only in the villain business for her own pleasure, she could care less about the fight between good and evil.
An extremely overweight, but surprisingly agile ninja that is promised by Wuya and Jack Spicer that if he retrieves a Shen Gong Wu called the Sword of the Storm then he will be able to join the Heylin.
An ancient evil demonic warrior made up of the Helmet of Jong, the Heart of Jong, the Two-Ton Tunic, Jetbootsu, Fist of Tebigong, Third-Arm Sash, Shroud of Shadows, Eye of Dashi, Logi Kite, and possibly any other Shen Gong Wu it can acquire.
All Your Powers Combined: Has each power of the Shen Gong Wu that makes up its form. In its initial appearence, this is limited to...
Curb-Stomp Battle: Easily steamrolls most people it fights in it's first apperance. Subverted in the second in that while the monks still have difficulty with him and the other jongs, they aren't nearly as outmatched as they were the first time.
Four Is Death: The amount of Jongs it splits into, called the Fearsome Four.
The Juggernaut: In his first appearance alone he defeats every last experienced monk at the Xiaolin temple, Master Fung included, then easily beats Raimundo and takes the Sword of the Storm from him, and once he's led by Wuya to where the monks-in-training are, he easily takes the attacks from every Wu they use against him and eats the orb of tornami. The monks only beat him because Omi was able to rip the heart of jong out with the golden tiger claws, and had he been noticed, they would have been dead.
Me's a Crowd: In its second appearence, it gains enough Shen Gong Wu that with the Ring of Nine Dragons, it splits into more Jongs.
Cut Lex Luthor a Check: Unlike other villains, who have grandiose schemes for world domination, Pandabubba uses Shen Gong Wu for relatively mundane, but illegal, money-making ventures, like arming his thugs with Wu to commit crimes or mind-controlling people into a workforce of slave labor.
The Juggernaut: In his first apperance. He easily defeats the monks up until the final showdown of the episode. In later apperances while he's still rather powerful, he's also far less impossible to defeat.
A particularly dangerous Sheng Gong-Wu that, when activated, turns into an actual blue dragon that proceeds to zombify and enslave everyone it comes across, and as such is to be used only after everything else has failed.
Ambiguously Evil: Although it is potentially a very serious threat and definitely goes about its schemes in an intelligent manner, its not clear if the Sapphire Dragon is sentient or, really, what it even is in the first place. Its likely an evil dragon Dashi somehow imprisoned, but its not entirely clear.
Dreamweaver: In the episode Dream Stalker, Hannibal Roy Bean fuses it with the Shadow of Fear via the Moby Morpher and uses it to attack Raimundo in his sleep.
Hero Killer: Effortlessly defeats all four main characters as well as Master Wong and every other monk in the temple, though admittedly this was early on in the show. The only one who manages to defeat it is Dojo of all people, and he survived by luck as much as anything else.
It Can Think: Although it doesn't talk at all, it manages to take over the Xiaolin temple through stealth and guile more than through brute force. For a once-inanimate object, it is quite clever.
In its second appearance, the Sapphire Dragon actually called a Cosmic Clash Showdown.
The Juggernaut: While Dojo managed to injure it with his claws, it still wiped the floor with the entire Xiaolin compound and the more people it enslaves, the more powerful it becomes, so in the long term it could become an Invincible Villain.
Omnicidal Maniac / Zombie Apocalypse: There is no indication that the dragon ever planned on stopping, meaning that it might have ended up turning everyone in the world into its mind-slaves.
Weaksauce Weakness: Soot can harm it and its minions, and enough can return it to Wu form, hence why Dashi hid it in a volcano. Though it is implied that if it ever enslaved enough people, it might be strong enough to eventually overcome this.
A French mime. He possesses magical powers which allow any object he mimes to manifest as a solid, but invisible construct, ranging from an imaginary lasso to an invisible box. These constructs can be altered by the imaginations of those who come in contact with them, such as the Xiaolin Dragons imagining a door to escape a box he trapped them in.
The Cameo: Made a brief appearance in the first part of the series finale, being enslaved by Jack Spicer.
Imagination-Based Superpower: When Le Mime pantomimes, what he creates becomes real, if invisible. Interestingly things he creates can be influenced by other people's imagination as well.
Your Mime Makes It Real: Le Mime is capable of making invisible objects by simply miming them into existence. It's shown though that these objects can actually be changed ever so slightly by others if they mime new characteristics on said objects. Such a case happened when Raimundo mimed that the perfectly solid box he and his fellow monks were in had bars.
Ambiguously Gay: The henchman in the white suit. It was even planned for him to say to the other henchman how much he enjoyed flying with him in the episode, but it got the cut, due to the very obvious implications.
Sealed Evil in a Can: Within the Mosaic Scale Shen Gong Wu. His episode has him accidentally unsealed with the Mosaic Scale being broken in half after being dropped a great height, and resealed by Kimiko using her fire power with the Eye of Dashi to weld the Shen Gong Wu together.
Yodel Land: Half of the time, him saying something is the stereotypical yodeling piece. The other half is him talking in an accent suitable for Yodel Land. He even wears suspenders and pants! The only thing he's missing is a Tyrolean hat, as he wears a bucket instead.
Anti-Hero: He's rather trigger-happy since his first appearance has him shoot explosives at Dyris when the Xiaolin Dragons just saved her from the freezing water, so they naturally defend her from him. He's also quite scary-looking. Once Dyris' true nature gets elaborated on, he's firmly in the right.
Taking You with Me: He holds Dyris with him as the iceberg they're on collapses, causing them both to be frozen in ize in the arctic ocean.
Top-Heavy Guy: His abdomen is even very narrow right at the top of that area compared to his breast and shoulders (roughly a third of their size from left-to-right), making the cutoff point of his body's larger mass higher up than most examples of Top-Heavy Guy.