How many times can you do an episode about friends distrusting or betraying friends? Judging from the writing for this show, more than a few. Virtually every character in this show is shallow and petty. They bicker and squabble over things like who gets to use a certain weapon. At one point, Raimundo, who is clearly one of the worst characters on the show, chooses to betray his "friends" when he doesn't get a medal for his training. That's as if to assume that Xiaolin training is supposed to be a cakewalk in the first place. Of course, he doesn't betray them for long, but really now... Wouldn't something as drastic and recurring as that start to sway your trust in that person? Apparently not, but all the characters in this show are routinely dense, if not completely braindead.
Speaking of his "friends", there's no real sense of friendship between the characters at all, mostly because they're too busy backstabbing or childishly taunting each other. They're more at odds with each other than anything, and each one only has faith in his or her own abilities, almost completely barring any concept of teamwork. In one episode, the others get trapped by a mime, and Clay has to fight alone. Rather than rallying behind him, they practically admit defeat, acting as though their "friend" is completely worthless, even in spite of what their own master had to say about him. For a kids show that's supposed to emphasize good morals, this one stresses very little of them.
And since I brought up "fighting"...there isn't much of it at all. The show is more about the characters running around and trying to nab all the Shen-Gong-Wu's. Most of the action sequences amount to a chase, or something equally non-violent. In the few instances where there is fighting, it's with robots, because hitting other people is bad, right? Right?
The animation doesn't fair much better. It's a western animation style that tries to incorperate some eastern animation influences, often with disasterous results. Characters do wild takes that are just absurd, but for all the wrong reasons. In general, the art style itself is a mish-mosh of different styles colliding together haphazardly, borderlining on a train wreck. Compare Kimiko's pointed chin to Raimundo or Omi's spherical, Charlie-Brown-esque head, and it doesn't even seem like they belong in the same show together. I don't have a problem with the character design itself, but in terms of art style, 'Drawn Together' has more continuity than this.
In short, Xiaolin Showdown needs a lot of work in order to become a well-rounded show. For starters, they need to decide what direction they want to go with it and GO there. I don't expect a kids show to have incredibly fresh writing, but many of the themes of this one were stale the *first* time they did them, and repetition didn't make them any better.