Here is an easy way to beat Kaiba: Kaiba must go first, and he cannot play any facedown cards. There is a slight chance that he may just play Cyber-Stein and use its effect to summon his Blue-Eyes Ultimate Dragon. This effect will reduce his lifepoints by 5000. Now, you will have to have the Change of Heart card in your hand. Play it and take control of his Blue-Eyes Ultimate Dragon and attack his Cyber-Stein. This will do 3800 damage to his lifepoints and you will win.