YMMV / Yu-Gi-Oh! Dark Duel Stories

• Game-Breaker:
  • Change of Heart. Its effect in this game is permanent instead of only lasting one turn like in real life, so you can steal your opponent's best monster from them for the rest of the duel if you use it right.
  • Thousand-Eyes Restrict. It's a normal monster in this game, requiring no tributes, which steals your opponent strongest monster, and increases its level by 2 (equivalent to a 1000 ATK/DEF boost), so you can deal massive amounts of direct damage right away. Broken for obvious reasons. Coupled with Change of Heart, Brain Control, and Relinquish, duels becomes a "I steal your monster, you steal my monsters" game against the tier 4 / 5 opponents.
  • Dark Hole is one due to a quirk in the tribute mechanics. You're allowed to tribute monsters, play Dark Hole, then tribute summon a monster in that order. Played with minimal monsters on your field to tribute, Dark Hole becomes cost free.
  • Cocoon of Evolution will evolve into Great Moth after a turn on the field, which then evolves into Perfectly Ultimate Great Moth the turn after. With its high defense for a 3 star monster, it'll likely survive long enough to change once. Finally, the Cocoon can be used once your Duelist Level reaches 60! This is low compared to the benefit this card gives you.
  • Some Card Creation monsters can have very low deck cost, while being level 4 or below but having stats you'd expect from a level 5 or 6 monster.
• Nightmare Fuel:
  • The animation if you or your opponent wins with Exodia is terrifying.
  • The Rare Hunter/Seeker has one of the most creepy-looking mugshots in the game, which is made worse when Marik possesses him and he talks in all capital letters.
• That One Boss:
  • Simon Muran/Paradox. His deck is full of magic cards that can reverse the flow of the duel, and he gets them with shocking frequency. Brain Control to take your strongest monster for an attack or tribute, Crush Card Virus to wipe out your field of powerful monsters, Spellbinding Circle can weaken all your monsters to make defeating them easier, and Dian Keto the Cure Master to restore 5000 of his Life Points for more chances to beat you. Oh, and he has 3 copies of Brain Control, Crush Card Virus, and Spellbinding Circle to hit you with. All of this on top of a solid Light/Dream Deck that uses Bright Castle to increase the power of his monsters, and Simon more than earns his place here.
  • Ishizu Ishtar. She uses a female monster deck like Mai, but is significantly more powerful due to her potent magic cards and stronger monsters. She runs 3 copies of Dark Hole, and her A.I. is smart enough to play them before summoning a monster to attack you directly with. Next are her 3 copies of Megamorph and Spellbinding Circle, using the former to power up her monsters one at a time without a type restriction to hinder them like similar cards and the latter to weaken all your monsters at once. She even runs 3 copies of Swords of Revealing Light, giving her a potential 9 turns to stall and build up her forces while you sit there and pray for her current copy to end before she uses another.
  • Priest Seto is ridiculous, even compared to his fellow Ancient Egypt bosses. He uses almost the exact same monsters Seto Kaiba uses in Domino City, so get ready to eat Blue-Eyes if he lands it, and possess far more powerful magic cards as well. He stocks 3 copies of Dark Hole and Raigeki, giving him 6 total field nukes to play against you, and Raigeki leaves his field untouched. 3 Megamorphs to power any monsters of his he wants, meaning his beatsticks like Blue-Eyes White Dragon hit harder. Most dangerously, he possess 3 copies of Change of Heart, which is a Game-Breaker in Dark Duel Stories because it's permanent unlike the real life card. He can either steal up to 3 of your strongest monsters from you to beat you with, or tribute them for one of his own monsters.

---