Finally got back into Soul Calibur after taking a break from what used to be one of my favorite franchises since the 3rd.  The reason I gave it up was because the series wasn't really evolving.  But, at the same time, I couldn't really think of a way for it to evolve.

Soul Calibur was practically perfect IMO.  Soul Calibur 2 improved it slightly by allowing you to use multiple weapons per character and adding Link for the Gamecube master race, but the core game was essentially the same.  And in 3, it was still more or less the same.  I didn't think it was laziness so much as there not being anywhere left to go.  They nailed it on the first shot (well second).  And they obviously wanted to keep making profit off the great core game they made, but there wasn't much to improve.

So finally back in 6, and not all that much has changed.  You can now shred your opponents clothes (which I probably enjoy way more than a healthy well adjusted man should) and they have super moves and a powered up state now which are... ok.  And a rock paper scissors mini game which is kind of meh.  After so long I'm having fun getting back into it, especially with the online mode (hit me up for a match) but I'm reminded of why I took such a long break, and why I'll probably skip out on Soul Calibur 7.  They just peaked too soon.  

Are there any other franchises you could think of where an early entry was so good that the developers had no place to go with it?

probably devil may cry, the original. It;s been a letdown to me since.

I sort of agree, although I'd say it peaked with three.  Four was more of the same, and five seems to be too so far.  Still fun though.  

I sort of appreciated that they tried something different with DMC for this reason... but that game was just kind of pretentious.

While on the subject of Capcom, I'd also add Dead Rising.  The weapons were fun in the latter games, but the tension died out and it felt more like a beat em up than a survival horror. 

Suikoden series. The second was such an amazing game that the 3rd seem bad in comparison (even through I think it actually was a decent game but a huge drop off from the second). The 4th one was just bad don't think I ever finished it. Never played the 5th.

Dynasty Warriors 3. It was the peak too early, all they had to do was keep making more just like it with slight improvements and they tried with DW4 and DW5. But then they actively made it worse with each entry, with the pit being DW6. It has been a slight incline ever since, but they still have yet to come even close to the peak again.

Online functionality was the main reason I bought Soul Calibur 6 so that's true enough, but I was more thinking of improvements to the gameplay itself.  Dunno if you're right about sales of fighting games though.  In my younger days, I was content to play Soul Calibur for hours a day just against the computers.  I'd imagine more people then you'd think still buy fighting games just to do that or play local multiplayer.  

Edit:  Also though Soul Calibur 2 does have a version with added online play.  Was tempted to go for that, but I figured the userbase would be bigger on SC6 and even with that it takes longer to find a match than I'd like.

I might have to give 5 a try at some point then.  I liked the first one a lot and you saying you liked the 5th more.  My only fear is as I get older my patience for JRPG is not what it use to be.  I finished Dragon quest 11 but other then that it been awhile since I made it through one.

I just revealed it as my #5 game, I speak a lot about it and Wu was certainly my favorite. Gan Ning's ultimate weapon was just straight fun too with the extra lightning effects.

Damn, I miss dynasty warriors. The last one I played was 5... 

I'd say it also peaked with 3, especially with extreme legends.

I did quite enjoy 4 though as well. 

Not an early game in the series, but I’m afraid that Smash Ultimate will suffer from this. With so much content and ‘everyone is her’ plus more, where can they go for Smash 6?