Scorpion could have been the main boss in the second Mortal Kombat, that how big of a pain he was on single-player. My memory is bad but I recall Kintaro and Shao Kahn being easy compared to him. Especially if you're playing Sub-Zero and just spam freeze the hell out of them. My brother used to always freeze Kintaro right when he was jumping and then got a free kick in.