Seishirou Momoi

Is said to be the best swordsman in the area, calls himself "human lightning" (or "human electricity"). Mugen figures that a strong fighter will attract the tsujigiri, so he catches up with him strutting down the street with his flunkies. Seishiro assumes that Mugen is the tsujigiri, watches his flunkies get taken out, and begs for his life, saying he made up the nickname.