I really like that Kaiba is just as horrified by this as everyone else is. He was all for the two of them dueling, but pitting them against each other in a battle to the death is another matter altogether. Once upon a time, and especially in the manga, he wouldn’t have cared and would have even done the same thing himself if he had the chance. After all, he tried to kill Yugi himself in the manga. That he reacts this way now though really shows how much his mindset has changed.
Also I think another part of it is that he just won’t tolerate anyone trying to hijack his tournament and pulling this kind of dishonorable crap.
"Once upon a time, and especially in the manga, he wouldn’t have cared and would have even done the same thing himself if he had the chance."
In his own words:
"Even at my worst, I would never have done this.”
And that’s because Kaiba has a sense of fairness (even when it’s totally bananas) that Marik does not. Keep in mind that all of the Death-T games, Yugi can win. It is possible for him to successfully complete all of Death-T without harm to his person or his friends (minus Grandpa), without breaking the rules or taking a third option.
And this is not true in this game. If Yugi wins, he loses. If he loses, he loses. The way this game is set up, no matter who wins the duel, someone is dead and Marik wins. They have to break the rules in order to survive.
And that’s what Kaiba is commenting on. In his opinion, it cannot be defined as a “game” if one of the players cannot win. He’s pretty indifferent to when the odds are stacked against one of the players, even even to the point of ludicrousness (that makes it a ~challenge~), but there’s got to be a way.
That’s a very good point! I was only thinking of it in terms of how Kaiba was quite willing to kill people back then and the way he treated Yugi, but the way you put it makes a lot of sense. Games have always been extremely important to Kaiba, so it makes sense for him to be opposed to a situation that no one can win in. I guess his philosophy about that was kind of like Yami Yugi’s then. Yami always set his games early on up so his opponent would have a chance at possibly winning if they played by the rules.