Nightmare Fuel / Yu-Gi-Oh! Monster Capsule GB

• The intro to the game details the Millennium Ring possessing Kaiba, and the start of the game proper has Kaiba performing a ritual that traps Yugi's friends in figurines.
• It's ambiguous as to whether Mokuba knows Yami Bakura has possessed Seto or not, as he works for him in the first level of the game, but Yugi only finds out about Bakura's involvement when Mokuba tells him about it before the last level.
• Before you go to fight Kaiba, Panik approaches you for a capsule monster duel. Losing it apparently kills you and you get a game over, and attempting to surrender the match gives a warning that it'll kill you.
• Seto Kaiba's RPG world is a literal representation of Hell that starts with Yugi being captured and goes downhill from there.
• After you defeat the Blue-Eyes Ultimate Dragon and return to the real world, Kaiba fights against the Millennium Ring's control, screaming. It uses the same shot of Kaiba's Mind Crush from the manga with the Ring edited in, and the screen flashes white intermittently.
• In the postgame, Shadi's team is composed of Yugi's friends as figurines.
• In the postgame you can fight Yami Bakura properly, and losing has Ryou desperately fighting against him while he screams at Yugi to run.

---