Why did the hole in Kaiba's chest increase in size? Starting out, we see that there is a pretty significantly sized hole in Kaiba's chest. Later on we see in a flashback that the hole was much smaller when he first showed at the Issoudan base. 



The collector of Warp's clones mentioned that the hole is one of the indicators of a true clone, and we see that the clone in the final battle also has one. Why would the hole in Kaiba's chest have changed sizes over time?
I can't say for sure, but IMO, the hole size probably varies depending on a Kaiba/Warp's mental state — the worse he feels, the wider it gets.