There came a time, that if Seto Kaiba were to remain Seto at all, he'd need to let go.
He'd need to let go of the hatred he held in his heart for anything less than total control and perfection, for working together and having more on his mind than the next competition.
If Seto Kaiba remained the same, he'd be lost to his own quest for power.
Kaiba Seto would only be Kaiba, and not much would separate him from the man he so despised, his stepfather.
He would no longer be the brother he'd promised to himself he'd be for Mokuba.
Kaiba Seto would be taken over by everything he hated, and there'd be little saving him.
That's why, standing together after Battle City, he vowed for a new start. One where him and Mokuba would truly be together as a family. They'd build KaibaLands all over the world like they'd planned.
Kaiba Seto would let go of his hate and resentment, a little at a time. And learn to have fun, as Jounouchi had tried to teach him.
He had so much care he wished to give but he'd forgotten it along the way. He wanted to help children who'd been orphaned like them.
He wished to bring joy, not the bitterness that swelled in his heart when he thought of what Gozaburo would have said to him, and the misguided quest for power he'd set him on. All in the guise of security and glory.
There was no glory if it meant hurting his younger brother, never smiling with him and forgetting the dreams they'd cherished together.
Kaiba Seto would need to learn to be a good friend, to himself and his brother, and to those around him.
To remain Seto, he'd learn to be a kind brother again, duel just for fun and be a good friend to those who helped him along the way.
Kaiba Seto would need to change, if he wanted to remain Seto at all.
He could no longer hold Seto at arms-length, he'd need to embrace himself, once again.