In Mega Man 2, which robot master gives the Metal Blade weapon?

In Mega Man 2, Metal Man gives Mega Man the Metal Blade weapon. Metal Man is one of the eight Robot Masters created by Dr. Wily for the game.

The Metal Blade is a rapidly thrown, circular saw-like projectile that can travel in eight directions. It uses very little weapon energy, making it one of Mega Man 2's most versatile and powerful special weapons. After defeating Metal Man, Mega Man can equip it and use it against enemies and other Robot Masters.

A memorable design twist is that Metal Man is extremely vulnerable to his own weapon: the Metal Blade can defeat him in one hit on Normal difficulty during the rematch. Bubble Man gives the Bubble Lead, Flash Man gives the Time Stopper, and Quick Man gives the Quick Boomerang, so those names are associated with different special weapons.