@Sephiroth0812
I see, thanks for the refresher. The one potential "plothole" is indeed that Roxas doesn't have a keyblade. But then again I'm not so sure about that. It's not like Sora uses Ven's keyblade when he calls a second keyblade (Unless it somehow just is and Sora's different keyblade chains are giving it a different shape). So I'm still no so convinced that a heart that can wield a keyblade isn't enough. (and yea, I though of Xion too. And whether a person believes it to be canon or not, he used 3 keyblades in KH2 final mix when fighting Roxas)
That is
exactly what both Sora and Roxas are doing when they dual-wield. That has been confirmed in the BBS Ultimania. The two Keyblades in use are always Sora's and Ven's. Sora and Roxas even both wield Sora's Kingdom Key at the same time (during Chain of Memories) because of their close special relationship. This was also plainly stated in an interview (either from CoM or from KH 2). Ven's Keyblade came only into the mix when Xion disappeared as the shock and emotional turmoil Roxas felt at this event were so strong that he accidentally accessed Ven's sleeping heart and unsealed his Keyblade.
Xion's "Keyblade" on the other hand was never more than a cheap sham, as confirmed by Riku in-game during Days, a fake that could only function because she was siphoning Sora's memories of the Keyblade to power the copy.
As for TAV, it's not KH3 Sora that makes them look weaker in comparison, it's all of BBS.....That's why I don't like it nearly as much as KH2. They're supposed to be master level, but endgame KH2 Sora is more powerful in combat. Look at Lingering Sentiment from KH2 Final Mix, and then Look at Terra in BBS....the difference is so night and day it's borderline embarrassing. But I see Lingering Sentiment as a preview of what TAV will be like in KH3 (and that was 10 years ago!), so I wouldn't worry about that at all.
Also again, as Sora levels up in KH3, so will enemies and bosses. Remember when Nomura made Osaka team power Sora down because there was a point where just "moving around made him invincible"? Even Nomura was a little concerned about how powerful Sora was becoming during the development oh KH3, so I don't believe all of his abilities will result in him being overpowered since they are paying close attention to this kind of thing. They stated they intentionally made the trailer flashy this time, since they could only show so much (they wanted to show more). Gameplay won't look like that at all times. There were also no working MP or "EX" gauges. In the real game, you won't be able to spam powerful moves and mechanics, so you won't just effortlessly destroy everything in your wake lol It'll all be fine

And if Drive Forms do come back in some form, it's almost guaranteed that they'll be 100% optional like in KH2.
All that endgame KH2 Sora has is that everything is more flashier and over-the-top (like KH 2 in general is), lol.
Disregarding the obvious inferiority of the PSP hardware-wise, the attacks, techniques and abilities shown in BBS itself were suitably powerful, especially the shotlocks which some players even mark as overpowered as well. They just weren't as eyecatching as KH 2 (and there were no skyscrapers to slice apart).
Aqua fought Hades and a copy of the Ice Titan at the same time and won, faced Terra-Xehanort and the giant Heartless in the Dark Realm, Terra held his own against MX and Vanitas together while Ven went one-on-one with Captain Hook, Maleficent in her human form and an X-blade-wielding Vanitas, all no small feats that can certainly put on the same level of respect than most of the stuff Sora pulled in KH 2.
This
presentation is what throws people off and has many claim that Sora is stronger (and of course the notion that he's the protagonist and the protagonist
has to be always the strongest because reasons).
Moving away from solely the BBS-crew though, the same issue applies also to Riku, Mickey, Roxas or any of the major villains as well, and most of those
did already have their debut in a "big" console title.
Even when looking solely at KH 2, I guess no one can deny that despite being said to be on roughly equal level of power, what Riku can do and show during KH 2 pales
big time to what flashy things they made Sora capable of.
Mickey can do some Yoda-like jumping and shoot some light pearls, but otherwise you don't see that he's supposed to be a Master that surpasses both Sora and Riku.
It's true that maybe I'm overanalyzing, but KH 2 with its total overdone hollywood flashiness and overpowered techniques but close to zero real substance really rubs me the wrong way. It's gotten even stronger again since I could play HD 2.5 recently and see it again in all its glory. The only thing that is really a challenge difficulty-wise in KH 2 are the Lingering Will and the Org Data-battles. Even Sephiroth is a walk in the park if you use everything that you have at your disposal.
The last game I remember were enemies actually level up just like the player does was FF VIII, whereas in KH the only games I remember were regular enemies pose any kind of true challenges are KH 1 and DDD.