The costume of the character I thought of called Death-Shot, now people know what he looks like, of course different materials for the mask XP (Which is duct tape and black mesh)
it should work for Joker, but it would be best if it was purple. Joker is known for signature bight and dark colors. purple and green mainly. but since i'll be with you in my outfit, and you'll have the iconic face paint, you should be good. you might want to see about wearing some kind of vest though, good t, and of course matching pants.
Hmmm, got any advise for type of vest, and pants?
just a normal men's vest, but it works best in bright colors. maybe if you just have some regular one you could cover it with duck tape or something. I have one, it's like grey purpleish leather, but it's a 1x. doesn't fit me, but it might be too big on you. try goodwill though or saint vincent's. as for pants, bright would work, purple or green, or black if you don't have them or can't get tm. looke Joker pics, you'll get all kinds of good cosplay and ideas.
(Think of the mask however for when you think of death-shot, and make it a gas mask..... no fighter in his right mind would use duct tape as protection, 'less it's a fist fight....)