I'm not sure why being able to teleport to where the audience is too much of a stretch given Rai is described as 'speed of light'. If you got that kind of speed it should be pretty easy to run to just about anywhere to return any shot. I mean Ryoma can run up where the ref is sitting at to do Cool Drives, and he actually has no inherent speed techs (though he is surely very fast). We know Ryoma's speed is slower than the teleport speed of the Higa guys (otherwise he'd have no reason to copy that tech against Atobe). Rai seems to be obviously another tier above Higa teleport speed, so why shouldn't you be able to run to where the audience is with that kind of speed?
So far as ridiculous improvements go, I do not subscribe to the stuff like "Ryoma/Fuji can never lose by necessity of plot', but it's clear these two gets unusually high improvements when facing superior opponents. This is probably because they start out with lowish stats as the underdog. Compared to that, if you take say Tezuka or Sanada, they rarely start out as the underdog (Tezuka is sometimes underdog as a function of his previous injury, but never as a function of his stat against someone not in his tier) and their stats are generally far superior than anyone they face, so they rarely get any meaningful improvements. Note that prior to NPOT the improvement to Sanada/Tezuka are just 'I decided to unseal a previously forbidden tech', i.e. they didn't actually improve any. Fuji obviously improved a ton from pre semifinals, to semifinals, and finals.
---------- Post added at 08:44 PM ---------- Previous post was at 08:32 PM ----------
http://read.mangashare.com/Prince-of-Tennis/chapter-364/page013.html
http://read.mangashare.com/Prince-of-Tennis/chapter-364/page014.html
These are the the explanations we have for Hoshi Hanabi. Hoshi Hanabi is (so far, the ultimate Counter) and you guys are brushing it off like it's an easily returnable technique.
Before you Sanadaists read this post yes I know the prerequisites for Hoshi Hanabi would make the chances of Fuji hitting a Hoshi Hanabi against Sanada very unlikely. Even so:
http://read.mangashare.com/Prince-of-Tennis/chapter-364/page012.html
The way I see it, it crash lands at a very, very high speed. Not too good with space stuff, but the drawing of the ball is like a meteor. This leads me to believe that it's an instant technique, just like Sanada's Rai teleportation. We haven't seen him teleport into the air which means to return this he'd need to teleport out of the court and then into the stands to return it. Assuming his legs don't give out and he makes it, it would require much more power and technique than usual for Sanada to Rai it back onto the court... I mean of course it is Sanada. Not saying he can't do it.
What I am saying is Hoshi Hanabi isn't returned just like *that*. Once the cord ball is hit, it's almost a guaranteed point. Fuji hax FTW
The problem is that Tezuka, Sanada, and Yukimura all have this inherent property of 'returning crazy shots like it's nothing'. Niou, when copying Tezuka, returned 5th counter as if it's nothing and 5th counter sure sounds like a pretty crazy shot too. You can't base on how hard a shot is return by its description because otherwise half of the shots in POT shouldn't even be returnable. How many times have you seen soandso use a technique that's said to be unreturnable and then his opponent does a power up and hit it back like it's nothing?
While Fuji is certainly destined to be in the "Tezuka-tier", he has yet to be recognized as one of these members by someone of the Tezuka-tier and that's pretty much the only way you can get into this club. The closest recognition came from Shiraishi but again he's not a Tezuka-tier character (though he's also very close). Yes random guys are always saying how awesome he is but random guys also say one of the Fudomine fodder guy is as much a genius as Fuji, so if we buy the opinion of random guys that means Fuji must absolutely suck at tennis. I swear some random spectator must have said Kaidoh is stronger than Tezuka at some point (yeah right). The point is, you can't take the opinion of anyone outside of Tezuka-tier characters when it comes to evaluating potenital.
While his moves certainly look Tezuka-tier worthy, someone in that tier (Yukimura, Sanada, Tezuka, and Atobe) has to formally invite him into the club or he'll always be susceptible to the 'Tezuka-tier guy return the shot like it's nothing", like the Niou vs Fuji game (and Niou's clone isn't even close to Tezuka tier honestly). Atobe got in when Yukimura interrupted the game where he just learned World of Ice, and no one else at this point has been invited to the club yet.
And of course in the end you can just say Sanada doesn't hit cord balls on purpose so even if this shot is 100% unreturnable it'd only have a minimal impact on the game. 6th counter seems to only be developed to deal with Shiraishi who purposely hits cord balls to counter 5th counter. But if you can hit 5th counter cleanly over the net (no reason to assume Sanada can't do this), you wouldn't exactly get very many opportunities to do the 6th counter.