If you'd like to see the character's move list, see the image file included in the download.

This mod is intended for use with the Clone Engine created by Gneiss (@gneiss64). Please download that beforehand as the character cannot be used without it.

The link to download the Clone Engine can be found in the description of the following YouTube video:

https://www.youtube.com/watch?v=qMjbiv6j9U4

If the "Community Edition" modpack has released by the time you are reading this, you should probably just go download that instead if you're not familiar with installing this stuff, as that comes with a large number of pre-prepared characters, including this character.

If either that isn't out yet (at the time of this writing, it is not) or you just want this character as a standalone, you can install him by doing the following:

Drag and drop the "NativePCx64" folder in your "ULTIMATE MARVEL VS CAPCOM 3" directory. This will put Thing's files into your game.

You will then need to open your Characters.ini file that comes with Clone Engine and add the following to it:

[CharacterX]
CharacterID=Thing1
BaseCharacter=Haggar
SoundID=thi
NumColors=8
Child1=

Change "CharacterX" to be whatever ID comes after the most recent character you've added to Clone Engine. For example, in my build the character before Thing is Leon at spot 36:

[Character36]
CharacterID=Leons
BaseCharacter=Chris
SoundID=chr
NumColors=7
Child1=

So I would change Thing's character ID to [Character37].

At this point the character should be in your game, but if you want him to be fully complete with proper Assist Names and his character theme, you will need to do some additional steps.

credit to Gneiss for writing the following instructions:

How to use the ASTBGMTool:
As it is a command line tool, these commands should be performed in the command prompt:
ASTBGMTool bgm [STQR file] [Stream batch text file]
ASTBGMTool ast [MSD file] [CSA file] [Assist batch text file] [Starting character index]

Arguments for bgm:
STQR file: The path to the STQR file that the streams will be added to. It is recommended that you use the original file.
Stream batch text file: The path to the text file that contains all of the stream paths to be added.
The output is a STQR file named BGM_New.stqr. You may then rename this to BGM.stqr and place it in the CloneEngine directory.

Example: ASTBGMTool bgm BGM_Original.stqr BGMBatch.txt
Please note that this is only an example of a valid use of the tool. An actual use of the tool may have different arguments.

Arguments for ast:
MSD file: The path to the MSD file that the assist names will be added to. It is recommended that you use the original file.
CSA file: The path to the CSA file that the assist definitions will be added to. It is recommended that you use the original file.
Assist batch text file: The path to the text file that contains all of the assist definition .ini files to be processed. Invalid file names are skipped.
Starting character index: The index in Characters.ini that the assist definitions will start from. This argument is OPTIONAL. If it is missing, the assist definitions will begin at Character1.
The output is a MSD file named AssistMsg_New.msd and a CSA file named AssistDef_New.csa. You may then rename these to AssistMsg.msd and AssistDef.csa and place them in the CloneEngine directory.

Example: ASTBGMTool ast AssistMsg_Original.msd AssistDef_Original.csa ASTBatch.txt
Please note that this is only an example of a valid use of the tool. An actual use of the tool may have different arguments.

Format of assist definitions:
Name1: The top line of the assist name.
Name2: The bottom line of the assist name.
Type: The type of the assist. This can be Direct, Shot, or Extra.
Direction: The direction of the assist. This can be Front, Upward, TiltUp, TiltDw, or Instant.