And Mokuba was foolish to fall for it. He knows Seto for much longer than that and this fake was enough to allow Noah to brainwash Mokuba, which resulted in using him as a meat shield because Noah was a sore loser.
Kaiba: I HAVE BEEN PROGRAMMED TO TELL YOU I DO NOT LOVE YOU ANYMORE! ALSO, EVERYTHING I EVER TOLD YOU WAS A LIE. Mokuba: Does that include the part about loving me? Kaiba: NEGATIVE. Mokuba: Awww Noah: Initiate bitchslap subroutine.
Technically partially this is how Kaiba feels he doesn't really need anybodies help and will do anything to get out of his Stepfathershadow and Yugi/Atem's shadow and become the very BEST IN THE WORLD
