The Adventures of Dr. McNinja, Volume Two: Surgical Strike

The doctor is back, and his prescription is revenge. There's a new drug on the street that gives all the abilities of the mysterious ninja. The man responsible is Frans Rayner, a Danish movie star who not only wiped out ninjas on screen throughout the 80s but made them nearly extinct in the real world as well.

No one's sure why Rayner's building a ninja army, but he makes it clear that he doesn't want Dr. Ninja to interfere when he sends his army to kill him. The only trouble is they don't kill McNinja -- they just make him mad.