Like Ryu and Street Fighter, Sub-Zero and Scorpion have always been strong relative to their games, especially Subz. Their combined strength is greater than that of Leon and Ada (Leon is likely the strongest of the four, but Ada is by far the weakest). Throw in the popular theory that the ninjas' rivalry does a lot more for them than Leon/Ada's, and you have a match with a clear favorite. The fact that MK is stronger than Resident Evil during the day makes it even easier.
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