It means Yami Yugi is basically saying: “If you want a duel, I’ll play by your rules — but either way, I’m going to expose your mind and defeat you.” In Yu-Gi-Oh!, that kind of line usually signals a Shadow Game style threat, where the loser faces a mental or spiritual punishment rather than just losing points.

What the line implies

  • “Game or no game” means he is not relying on the opponent’s terms; the confrontation will happen either way.
  • “I will unlock my mind” suggests he’s opening himself fully to the duel, using his Pharaoh-like power and intuition.
  • Against Bakura specifically, it also carries a darker meaning, because Bakura is tied to mind control, soul stealing, and hidden intentions.

In plain English

He is saying something like: “Whether you call this a formal duel or not, I’m going to confront you completely and reveal what’s really going on.” That sounds dramatic because the series treats duels as battles of will, not just card games.

Why fans read it that way

  • Yami Yugi often speaks as if the duel is a test of character.
  • Bakura is one of the few characters who turns a duel into a psychological battle.
  • So the line is less about a literal “mind unlock” and more about mental focus, confidence, and psychic confrontation.

TL;DR

He means: “I’ll face you seriously no matter what, and I’m going to push past the normal duel to beat you mentally and spiritually.”