There’s another thing that it seems as though people overlook - the implications of Ryou and Bakura’s introductory arc.
In the arc, Ryou transfers to the school for the first time. After a series of events in which we are shown that 1.) Ryou is incredibly attractive and 2.) He’s a bit of a loner who is uncomfortable with a huge amount of attention, we are shown that he is also in possession of a Sennen Item. Not super surprising, seeing as Shadi had been introduced before this point, but this Item is special in that it, like the Sennen Puzzle, contains a spirit who has a tendency to challenge people to games and use dark magic to mess with their minds. Unlike Yami Yuugi, however, Yami Bakura seems to have a mean streak. A… different mean streak than Yami Yuugi has.
In either case we get the intention that Yami Bakura will be acting as an antagonist.
I’m sure you know the next events - Ryou Bakura warns the main characters to stay away from him, they don’t listen and end up playing a table top role playing game with Yami Bakura.
Now here’s the important part.
Throughout the game, we begin to see that Ryou is actively fighting against Bakura, overpowering Bakura’s attempts to keep his consciousness sealed.
Furthermore, Ryou actually thwarts Bakura, outwitting the spirit and slipping in a game piece that allows for Ryou to have an external tool to assist in Bakura’s defeat.
And then finally, Ryou overpowers Bakura’s will, causing the destruction of the mind dice and resulting in Bakura’s defeat.
Ryou is sacrificed in the process, but due to the piece of his soul he placed in the White Mage Bakura game piece, he is able to restore himself.
Now, I’m going to explain why this is all important.
In their introductory arc, the first time we ever meet Ryou and Bakura as characters, it is established that not only can Ryou outwit Bakura, but that he is also STRONGER THAN HIM AND IS CAPABLE OF DEFEATING BAKURA, WHO GOES ON TO BE THE MAIN ANTAGONIST OF THE ENTIRE STORY.
This is intended to be our first impression of these characters. Needless to say that this entire sequence is promptly forgotten as Takahashi basically scrapped every character’s personality and redid it when card games and publishers interfered, but it’s still a really important part to remember about Ryou. He’s no push over. He is probably the single person who can defeat Bakura on his own.
Which is probably why he is also the only person who can wear the Sennen Ring.