Zero from Vampire Knight

red dude with pants on his head swings a green scimitar

an evil red ninja, with a green sword and blue pants on his head

A red ninja with a green sword. Also, he has a pair of blue jeans on his noggin.

red ninja with a red top and blue trousers holds a green sword

a ninja has a green sword...he's not looking very stealthy with his bright red shirt and bright blue pants!

a surprised robber

A criminal scum has been caught by a flashlight.

lupin the third