In their latest update, Bandai Namco got a bit creative with how you can unlock extra content for Tekken 8.
Perhaps after being inspired by a similar event in Street Fighter 6, where you could unlock a few goodies by fighting Woshige's V-Rival (the game's version of AI copy of the player), Tekken now offers you to unlock some fan art by fighting Ghosts of the respective artists.
Just hop into the Fight Lounge, and you'll be able to shake down some gorgeous pieces for Alisa, Lee, Paul, Reina, and Xiaoyu. Drawn by Kitty, LEEBBUNSIK, RUNEMASTER, KornArt, and Rica Diaz respectively.