I like the style of this poem. It is a prosey sort of a free verse; clearly spoken (I mean, written) sentences as opposed to extremely flowery, formal language. I think it's quite effective, the way you mix poetry with starkness. You both have things said poetically--"sadness that held them all in chains of iron"-- or straight out--"I lost a brother today". The theme is played out well, and I especially like the innovation of using dialogue. Real quotes add that much more candidness to a poignant poem, and I often find that quotes can be just as poetic as carefully crafted metaphors. (The tragic example of this which randomly popped into my head is a woman on the news after the Sandy Hook shooting, a mother whose child lived and who was just so grateful that "I can tuck my child into bed tonight.")
You also have a sort of a structure to your free verse; the stanzas are divided up in a way that not only looks good but that separates each individual scene/idea so that they don't overlap too much and can each stand out on their own.
There are a few places where I think your wording could be improved. "But to continue is in our best interests" would be a bit less awkward-sounding if you reworded and eliminated the infinitive, or at least changed its location to later in the line. Also, in "wrecked upon an ancient castle," I think the word you want is "wreaked", not "wrecked." Another instance is when you describe the Trio as standing "stiffly"--I can see why you'd use that word if you want to convey a certain uncertainty about what to say in front of everybody, a certain not-knowing-how-to-deal-with-the-crowd, but I am not sure if that's what you intended, given the context. Did you mean something more like "firmly"? Also, I personally would use a different word in the line "Beyond the three considered strong"--i.e. held/thought/believed instead of "considered", but that's really minor.
You have lots of lines that I really love, too. "With tired eyes and stinging wounds/And broken hearts and empty words" is a brilliant use of meter repetition, it just sounds really good when I hear it in my head. The line after it is good too, although if you added "they" between "And" and "were", the meaning would be clearer at first glance. Oh, and your stanza about the trio is lovely as well;; they're captured as the imperfect, exhausted heroes they are. And, wow, "So that's exactly what we're going to do, all of us, together" is such an amazingly mature/strong, yet absolutely Ron-like, quote!
Overall, I really enjoyed your poem! I like free verse with organized-ish stanzas, as a poet myself...even though it's not always my strongest suit at writing...:)
Wow! I loved it. Sad that I'm the only reviewer!
I love your vision of what happened after the battle. It feels sad, but hopeful. Nice job!