So this post isn't really a formal guide per-se (hence why I didn't title it as such), but I recently posted this information in a Discord server regarding ripping stages from this game, and I figured that it might be useful to some of you out there in internet-land (that, and I'm posting so this info gets indexed on search engines like Google, making it easier to find). I'm sure most of this is already familiar procedure to many of you, but hey: doesn't hurt, right? 
The format this game uses to store files is a proprietary archive format called FPK (shared among all of Eighting's games past starting around the PS2 era; this includes Tatsunoko Vs. Capcom, as well as a lot of the Naruto: Clash of Ninja games and the Japan-only Doraemon: Secret Gadget Tournament among others).
First, to get these FPKs from the game, rip your Wii disc on a real console using the homebrew CleanRip and get the resulting ISO onto your PC. Open up Dolphin Emulator (making sure you put your ripped copy of TvC somewhere Dolphin can find it) and right-click it, then go to Properties -> Filesystem; the stage files specifically are under `fpack/stg/(numbered folder)/0000.fpk`, right click one and extract it somewhere.
There's a couple FPK viewers (and source code) floating around on the internet, but I found a tool called GNTool (made for the aeformentioned Naruto: Clash of Ninja games but it works great for any of Eighting's other games) that you can use to extract FPK files. Download it here and open it.
Click the little wrench icon to bring up a list of utilities, the one we want is FPK Unpacker. Select your extracted FPK file, then select somewhere to extract its contents to. After a few seconds, GNTool will have done its thing and extracted the FPK's contents. You can now close GNTool.
Now to get the model and textures, I personally recommend BrawlCrate; a fork of the venerable BrawlBox. Download it here.
Open brawlcrate, then go to File -> Open. Wherever you extracted the FPK's contents, there should be a folder within there called stg, then a number, then a bunch of files; click the one labelled 00(some number).brres (you might need to try a few different ones in the file to find the one with the stage). Once you do that, you'll see a bunch of folders; the two important ones for us are 3DModels and Textures: in both cases, right click to export them somewhere (make sure both textures and model are exported to the same location, this will make it easier to import into programs like Blender), export the model as a .DAE and the textures as .PNG.
After that, you should be able to import the .DAE in Blender, which should also automatically apply the textures... kind of. See, Blender's import options are kinda weird in this regard and don't connect the alpha channel properly. The default import blend mode, Alpha Blend, is also pretty wonky in my experience and tends to cause all manner of problems.
After digging around a bit on StackExchange, I found this Python script that automatically connects the Alpha channels and sets the blend mode from Alpha Blend to Alpha Clip, producing the correct look. Open up the Scripting workspace in Blender, then copy and paste this script in the command section (you might need to remove the blank lines or else Blender might run the script early and throw a bunch of errors at you) and press Enter a few times to run it.
Hopefully some of you find all this info useful! I just wanted to make sure it didn't get lost in the annals of history, is all. Have a good day!
The format this game uses to store files is a proprietary archive format called FPK (shared among all of Eighting's games past starting around the PS2 era; this includes Tatsunoko Vs. Capcom, as well as a lot of the Naruto: Clash of Ninja games and the Japan-only Doraemon: Secret Gadget Tournament among others).
First, to get these FPKs from the game, rip your Wii disc on a real console using the homebrew CleanRip and get the resulting ISO onto your PC. Open up Dolphin Emulator (making sure you put your ripped copy of TvC somewhere Dolphin can find it) and right-click it, then go to Properties -> Filesystem; the stage files specifically are under `fpack/stg/(numbered folder)/0000.fpk`, right click one and extract it somewhere.
There's a couple FPK viewers (and source code) floating around on the internet, but I found a tool called GNTool (made for the aeformentioned Naruto: Clash of Ninja games but it works great for any of Eighting's other games) that you can use to extract FPK files. Download it here and open it.
Click the little wrench icon to bring up a list of utilities, the one we want is FPK Unpacker. Select your extracted FPK file, then select somewhere to extract its contents to. After a few seconds, GNTool will have done its thing and extracted the FPK's contents. You can now close GNTool.
Now to get the model and textures, I personally recommend BrawlCrate; a fork of the venerable BrawlBox. Download it here.
Open brawlcrate, then go to File -> Open. Wherever you extracted the FPK's contents, there should be a folder within there called stg, then a number, then a bunch of files; click the one labelled 00(some number).brres (you might need to try a few different ones in the file to find the one with the stage). Once you do that, you'll see a bunch of folders; the two important ones for us are 3DModels and Textures: in both cases, right click to export them somewhere (make sure both textures and model are exported to the same location, this will make it easier to import into programs like Blender), export the model as a .DAE and the textures as .PNG.
After that, you should be able to import the .DAE in Blender, which should also automatically apply the textures... kind of. See, Blender's import options are kinda weird in this regard and don't connect the alpha channel properly. The default import blend mode, Alpha Blend, is also pretty wonky in my experience and tends to cause all manner of problems.
After digging around a bit on StackExchange, I found this Python script that automatically connects the Alpha channels and sets the blend mode from Alpha Blend to Alpha Clip, producing the correct look. Open up the Scripting workspace in Blender, then copy and paste this script in the command section (you might need to remove the blank lines or else Blender might run the script early and throw a bunch of errors at you) and press Enter a few times to run it.
Hopefully some of you find all this info useful! I just wanted to make sure it didn't get lost in the annals of history, is all. Have a good day!