From Yu-Gi-Oh! look where the heart of the cards got him now...
Yugi (regular) : he is a very kind person who loves his friends and would never leave them. he is always talking with his special kuriboh's spirit as they are bff's. he is always thinking on the bright side but if he is ever feeling gloomy his friends or the pharaoh are there to cheer him up. His phrase (and really the phrase of every yu gi oh series dueler) is 'the heart of the cards!'
Yugi (pharaoh): He is the ancient pharaoh who was reincarnated into Yugi's body. The 2 souls share the one body and always keep each other company. When Yugi starts a duel he transforms into his pharaoh side. The pharaoh is very competitive and will win any duel at any cost if it involves the safety (shadow games*) of anyone.
Kaiba: No, kaiba does not have a pharaoh stuck in his soul, but his is filthy in all his richness. He is the owner of kaiba corp. (duh!) and invented duel monsters. He is ruthless and battles for pride. He will keep trying but only because he thinks he can beat yugi. Now with the help of this crazy scientist he can beat yugi. once and for all.
Yugi has a duel disk like any other typical duelist but he also carries a rare millennium item with him: the millennium puzzle. it is shaped like a pyramid and hangs around yugi's neck.
Kaiba has a duel disk but no millennium item ( :c )
Yugi and kaiba have been rivals ever since kaiba started the tournament and kaiba started suspecting that yugi could actually be stronger than him. yugi's grandpa owned a card shop so that is how yugi got his start dueling.