Where is Sora's adventure an echo of Ven's? They experience total different things on their journey's and have totally different outsets from where they start. The "my friends are my power"-bit is only one measly incident which serves to show how similar Sora and Ven are in their beliefs and you exaggerate that to levels as if Ven would be a manipulator/puppet master like Xehanort, despite only being there seeking protection after Sora allowed him to stay.I mean, rather then Sora making his own adventure, he suddenly turns into an echo of Ven's. "My Friends are my power" is great in KH1, but after Birth By Sleep you can practically see Ven subconsciously pulling the strings. Sora's adventure ceased to be entirely his own.
Completely correct.Except we know that is not the case.
Well, not really. It is kind of obvious that all of Sora's adventure is pretty much related to Ven, sure it's his own, but none of this would have happened(to Sora) if Ven didn't go in his heart. I know Terra influenced Riku to the extent he showed him a keyblade, but the Ven and Sora connection is pretty much one of the main things going on. There's many reasons to think that Ven, and others in(or were) in his(Sora) heart influenced things, memories, deja vu', abilities, etc. In DDD we even see (presumably Xemnas) saying to Sora something like " how can you be sure all those memories/feelings are truly your own ", so it is the case kinda.
That is however exactly Nomura's intention. He doesn't want Sora to be one highly special guy.
His adventures may be related to Ven in a sense, but they are in essence of course his own. The drive to find Riku and Kairi, help the worlds etc. was all Sora's own and not related remotely with Ventus.
Even if Sora didn't have Ven's heart, Ansem SoD would have come to DI nonetheless, Riku probably would have fallen to Darkness and destroy the Islands nonetheless.
So, the overall bigger picture is overachingly held together by Xehanort and his ties to Terra and Riku, respectively.
The beings connected to Sora may influence "deja vus" as you said, but that does not change anything about the facts that Sora made the journeys in KH1 and 2 on his own volition and made his own decisions and experiences.
It wasn't Ventus playing puppet master like Xehanort does with Terra's body, he is not even in a state to do that.
Sora's heart is deeply connected with Ven's since his birth, yet Sora developed perfectly fine as a kid during BBS.
Ven only gave Sora the ability to dual-wield, nothing more; confirmed by Nomura. He basically said that he didn't want Sora to be predestined to be the hero or anything special.
These statements contradict themselves in a way though, and Nomura's words on Ven's and Sora's connection have often been misinterpreted by the fandom.
Nomura says that he doesn't want Sora to be one special being with some special super-power. But Sora gaining, and more specifically, using the keyblade without ever having an inheritance ceremony severely contradicts that, it's a very special case.
Sora snatched Riku's destinied keyblade away when his heart was stronger than Riku's in KH1, that is a confirmed fact. However, what Nomura confirmed was that Sora didn't gain any special abilities from Ven's heart or that there was any inheritance on stuff.
That doesn't rule out Ven's heart influencing something indirectly just by being there.
Spoiler Show
– So, it’s not that “once Sora’s story is over the story of a new hero will beginâ€, but that the series will always have Sora as the hero, isn’t it?
Nomura: Yeah. One of the concepts of the series is that the hero Sora isn’t some special being, but a normal boy. Sure, his heart is connected to Ventus and the others, but other than that, he’s a normal kid that could have come from anywhere, that hasn’t inherited anything from anyone. I want to make Sora a character that will give the player the feeling that “even if I’m not some special being, I have the possibility buried inside of connecting with many others to accomplish thingsâ€.
He explains the connections between hearts (using Ven because it's the closest) as being something special, but that Sora didn't inherit anything from the connection. He doesn't rule out a sort of influence.