Well, that was a wonderfully short shot of adreniline. The last stanza caught me off gaurd, I thought I was reading a "nature" poem and all of a sudden I'm shipwrecked in the middle of some type of epic battle.
Very nicely done.
"With her champion striding by her side
A quick blow; her ship hits the harbor."
That's my favorite part. It jolted me awake on a sleepy Tuesday morning. Thanks for that buddy.
I, as opposed to others, found 'A seagull... ...make her stay,' much easier to comprehend than the first stanza. It makes sense that a seagull flies away home and that an onlooker would be dismayed, especially due to the onset of twilight. I think, the coming of night was very evident in here, as opposed to the first para.
Many reasons to that: i think, using 'Splash of light brought "by" a crash,' throws off the fact that the light is diminishing. Maybe, using "down" would help, because (I think) that would lead to the next sentence better (in my head, at least). And again, I thought '"bursts" of warmth' sounds more like an uprising as opposed to defeat, or surrender to Night.
Not much to say about the ending. Maybe adding 'follow' in 'Her horsemen follow in brilliant shining armor' and an 'and' in 'A quick blow, and her ship hits the harbor.' would sound more final.
And having said all that, I really hate to critique. But then, I like to hear honest opinions, which invariably mean some critique. I also get entirely defensive. I think you deal with all that way better.
May the writer's spirit flow through your soul ... :D