All right. I'm skipping a few episodes since the last one. dp 42, dp 43, and dp 44 are fillers.
One difference b/w the Hoenn region and the Sinnoh region is that while the Hoenn region had the attitude of something completely new, Sinnoh draws upon a few familiar things: a fair amount of the new pokemon are just evolutions for pokemon already known from prior regions, and then Gary's here. I think the way Paul battled Ash in their first battle, using Elekid's Protect to defend against Pikachu's Volt Tackle (which is exactly the same thing Gary did with Electrivire against Pikachu at the very end of the Battle Frontier), demonstrated that Gary wasn't going to be needed too much in terms of being a rival for Ash- Paul is already a technical trainer. So, I suppose the question is what can Gary add to the dp show besides a nostalgia factor. Well, his biggest contribution to me is that he makes apparent a difference b/w Ash's and Dawn's characters. Gary is Ash's Zoey (insulting thought, isn't it?), someone who freely gives Ash what always seems to be sound and logical advice, earning praise from Brock and Dawn. The only problem is Ash doesn't appreciate it. Not even a little. Dawn may admire Zoey to no ends, but Ash isn't the admiring type. He's much more confident in his skills, and he sees no reason why Gary should think of himself as a superior trainer or someone better at tactics (unlike Dawn with Zoey; Dawn straightaway wants to see Zoey as a superior coordinator). I really like this, b/c I think I'm somewhat that way myself. I have a bad habit of rolling my eyes when people heap praise on my peers for just "sounding" good, if that's understandable (like Ash, people don't really heap praise on me, either, so I don't have to worry about that). Of course, Gary is aware of Ash's indignation and provokes him a little out of fun, although he doesn't do that on purpose this episode-this one is much too serious for that.
The best thing about this episode is that Ash isn't completely wrong about his reckless style, despite how Dawn and Brock respect Gary's cool, logical plans. One Sheildon does get captured by Hunter J, and Ash's quick surprise actions at the end of the episode allow him to recover it. As Hunter J is escaping, though, Ash is enraged and has to be held back by Gary. And Gary is right to do so; the 2 could have gotten in serious trouble if they had attempted to stop Hunter J and her many minions from leaving. Gary and Ash needed each other for this rescue to work, as they balanced each other out. But while Gary takes the logical approach, you still have to appreciate the more instinctive reaction from Ash; he knows more horrible wrong-doings will be done if Hunter J escapes, and he wants to stop it. And well, I like Ash for that. That's why he's an amazing character, b/c his emotions and intentions are easy to read when something means a lot to him.
Gary makes a point of giving Ash credit for being who he is at the end of the episode (saying how important it was in rescuing Shelldon), and that's neat to see, especially b/c Ash is a little surprised. Gary probably realizes that part of Ash's annoyance with him is that everyone (here, Brock and Dawn) acts like he is the smarter guy of the 2. For sure, Brock and Dawn were not going to say, "Way to go Ash" for what happened in this episode.