The Final Answer

Two pairs of champions became a crowd of three as a pale male Fey joined the fray with euphoric eyes gleaming gold. Following this same pattern, the third was superseded by the fourth, nearly tripping on his robes as he eagerly scurried his way forth. 

The number of scrolls was in a steady decline, as was the number of battle crests available. If my maths was right, and if middle school education has yet to fail me, I surmised that each camp had at least a dozen champions on either side.

An even number of participants, for an even number of princesses, but only one odd winner, for only one odd prize. It's like poetry, it doesn't even rhyme… it's sure as hell poetic though.