Kentaro, the Smiling Cat
Legendary Creature — Human Samurai
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
You may pay 
rather than pay the mana cost for Samurai spells you cast, where X is that spell's mana value.
"The bonds of bushido will draw the dishonored back someday, and I will be there waiting."
Donato Giancola
Rulings
Kentaro doesn’t change when you can cast Samurai. It just makes Samurai castable for generic mana.
(wotc • 2005-02-01)
Kentaro’s ability only applies while Kentaro is on the battlefield. You have to pay for Kentaro normally. It still costs {1}{W}.
(wotc • 2005-02-01)
Rulings
Kentaro doesn’t change when you can cast Samurai. It just makes Samurai castable for generic mana.
(wotc • 2005-02-01)
Kentaro’s ability only applies while Kentaro is on the battlefield. You have to pay for Kentaro normally. It still costs {1}{W}.
(wotc • 2005-02-01)