As far as tag-teams go, I actually think the rivals aspect isn't a terrible take on it. The problem is, that tag-teams are a terrible idea to begin with.
Being a good implementation of a bad idea does not really make the rivals contest a good idea.
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http://images.wikia.com/finalfantasy/images/0/0e/Ffx-bahamut.jpg
Support Bahamut if we ever get another real contest.