Kentaro, the Smiling Cat

The marquee ability does not make Samurai cheaper; it makes them generic. Instead of paying a spell's printed colored cost, you can pay generic mana equal to its mana value, so the total stays the same but the color requirements drop away. That is a fixing lever, not a discount: it lets a Samurai deck cast a heavily-pipped or off-color member out of whatever lands happen to be untapped, ignoring the red or black requirements that a wide tribal manabase would otherwise have to support. The limit is the type restriction. Only Samurai qualify, so the payoff demands you build almost entirely around one creature type to extract anything from it, and a 2/1 with bushido 1 is fragile enough that committing a board of cheap bodies invites a sweeper to undo the whole plan. The bushido body and the casting ability both want you on the ground early: the legend you cast to smooth the curve of everything that follows, asking you to go all-in before you know whether the commitment is safe. He reads as tribal scaffolding, an enabler and a curve-smoother who leads the deployment rather than the threat you win on the back of.