Forget about MEGA. What you should do:
- download a clean Steam version
- go to http://w11.zetaboards.com/SFxT_Mods/topic/11172794/1/
- download the two packs in the latest AIO section (Game Update and DLC)
- download all subsequent game updates (updates 22, 23, 24, 25)
- inside the Game Update AIO multipart archive, there is a folder name called "Update", copy paste all of its content into the game's root folder
- inside the DLCAIO multipart archive, there's a folder named "Dead or Alive 5 Last Round", copy paste all of its content into the game's root folder
- then, for each update archives (22, 23, 24, 25) you should be looking for those files ("game.exe", "patch_XX_catalog.bin, patch_XX_catalog.lnk", "startup_setting.exe"), copy paste those files, archive by archive (starting with 22, ending with 25) into the game's root folder
- finally, inside the latest game update archive (the update 25 "DOAU110A.rar"), there should be a crack folder, copy all of its content into game's root folder
- download "Beach Paradise 5.06.7z" from https://mega.nz/#F!NFhG2bpJ!yZyIiHvuiHcgn1knT9p6lw
- once you have the archive, open it, look for "Dead or Alive 5 Last Round" folder, copy paste all shit inside into the game's root folder
And finally, go to the game's root folder launch "Launcher.exe", ET VOILÀ.
I really hope that helps.