Kuro of the 21 Blades

Vigilance, Bushi 5 (this creature comes into play
with x Training counters, when this creature
blocks or becomes blocked it gains +x/+x
until end of turn, x equals number of training counters.)
{w/b}{t} tap target creature, it gains a Training
counter and becomes a Samurai in addition to its
other types
Madness {3}