I'm not saying that Kaiba didn't deserve it, but there were times when Yami did do something against Kaiba that was just as much crossing the line. Even Yami Yugi himself can be an ass to Seto Kaiba. Okay, so Kaiba practically gave Yugi's grandpa a heart attack and sent him to the hospital. Yeah, because Yami's penalty game against Mokuba was NOT worse! I mean traumatizing a 12 year old kid for life by trapping him in a holographic egg and having him be stuck in an asylum for who knows how long with that nightmare is certainly not worse at least Yugi's grandpa only stayed there for at least a few seconds. How long was Mokuba trapped in that egg? A whole day? An hour? What about Kaiba's first penalty game with being trapped and attacked by duel monsters? I mean that even gave him nightmares that traumatized him. Yes, Kaiba deserved some sort of punishment, but it makes you wonder if what Yami did was really justice or him taking it too far. It's like a parent punishing a child. If he/she spanks the child, the child can use that to learn a lesson. If the spanking is so hard that it leaves a bruise or a scar, that's taking it too far to the point where it's abuse and not a punishment. You can argue the same with Yami's penalty games. If it traumatizes the criminal to where the punishent gives him/her nightmares, that's taking it too far. That being said, I do believe that Yami's mind crush was a good punishment for Kaiba, since it did help him instead of making him worse like the first penalty game. Though, the scar from the first penalty game is still there.