Nintendo vs SEGA
Connection:
Both iconic villains of famous platform videos games that lead an army (Koopas and Badniks respectively) bent on conquering the world (Mushroom Kingdom and Mobius, but are stopped by their main rivals alongside their sidekicks (Mario and Luigi to Bowser & Sonic and Tails to Eggman)
Both created robot replicas of themselves and have a doppelganger of the hero (Shadow Mario and Metal Sonic)
Both attempted to used powerful gems to achieve their goals (Pure Hearts and Chaos Emeralds)
Both reluctantly teamed up with their nemesis to defeat a greater evil (Dark Star and Solaris)
Both use similar vehicles (Koopa Clown Car and Egg Mobile)
Both play various sports with their arch rivals, such as racing
Both have traveled back in time, and even met their past self, to try and erase their mistakes from history
Both have kidnapped a princess (Peach and Elise) multiple times
Both of them also competed in the Olympics together and even appeared in Disney's Wreck it Ralph
