Disclaimer: I don't own Fire Emblem, nor anything connected with it. The following contains light spoilers.
The poem is set up in a form of modified villanelle. Its a difficult form to use due to the heavy reliance on a pair of repeated lines to do most of the work. The 1st and 3rd lines are repeated throughout the poem, although they can vary slightly. The rhyming isn't necessary to the form, but I decided to include it, causing a few word choices that may be confusing, but hopefully still sensical. Please let me know what you think of it, this is my first attempt at using this form, so I'm not sure how it came out.
Blazing Fire
The Medallion burned with a light fell and blue.
Enemies first, these mages two seen,
The wind and the light, the silver and green.
*
Branded, and wounded by two pasts unkind.
Unrest was growing, and the battles renew,
And the Medallion burned with a light, fell and blue.
*
They met first as foes on the field of the mind.
A chess match setting the scene,
Wind against light, the silver and green.
*
Upon castle ramparts they fought.
Dueling the other, and themselves too,
And the Medallion burned with a light fell and blue.
*
Some things will grow against all rational.
Found inside, the desires they glean,
The wind and light, the silver and green.
*
In the end together, the world to renew,
They fought the impossible, these two of between.
The Medallion no more burned fell or blue,
Together the wind and the light, the silver and green.