Red Oni, Blue Oni/Card Games


 * Magic: The Gathering: Red magic and Blue magic. Red magic, mages, and creatures are all about passion and defiance. Blue magic tends to be big on thought and planning. Also, fire magic tends to be red, while water magic tends to be blue.
 * Don't forget about the flavor of the plainswalkers! The two stereotypicals of this comparison are Chandra Nalaar's pyromantic Red to Jace Belleren's mind-bending Blue. Jaya to Karn (though Karn's technically colorless), Koth to Venser, the list goes on and on.