Both use the power of the so called "spirit" of Ionia, they want Noxus out of Ionia, but they both act in different ways. This brings a lot of grey areas of ideas, a lot of ambiguity to the match up, rather then just re-use the same concept of "Total control over Total destruction" thing with Riven VS Yasuo and Garen VS Darius. What do you say?
I would rather Kayle Versus Morgana( since they might get reworked before the next VS event) , Leona Versus Diana.
I think Karma vs Syndra would be a more likely match up, since they're both rivals. Power wise I wouldn't have thought Irelia would be on par with Karma in the lore, not in the same way Riven and Yasuo or Darius and Garen are.
Not really rivals in the lore and definitely not iconic as that.
VS 
would be my preferred match up, especially since it would take the VS event away from the medieval theme and bring it into times with higher advanced technology.
