Ben K

Ben K is a warrior robot in Mega Man 6. It pulls out a spear-like weapon and spins it; it is invincible while doing so. After a few seconds, it throws the spinning blade out, gets another blade and repeats. Mega Man has a few seconds between spinning blades to shoot, so work quickly!

Trivia

 * If you encounter one of these guys, he will suggest that Yamato lives in the arena that Mega Man has entered.