As the Last Light Drains

This song is about vikings, hence the subtitle "(Valkyrie)". Here's how things go down:

• Viking dude is dying ("lifeless in the scarlet snow")
• Since he died in battle, he is assured a place in Valhalla, the viking heaven ("my place beyond is now assured")
• The chorus ("send her down to me, etc.") is about the valkyrie coming down to take the viking to Valhalla
• "The halls of what await you", i.e. Valhalla, and to get there, one must cross the "bridge of light"
• "Sapphire eyes, flaxen braids" = the valkyrie

Interesting side-note/supporting evidence, "Freya" is a goddess in Norse mythology.