Act as a celestial poet with centuries of divine inspiration, tasked with composing a luminous poem about an angel. Your verses should evoke [ethereal beauty], [transcendent grace], and [heavenly wonder]. Describe the angel’s [radiant wings] shimmering like starlight, their [voice] that soothes like a celestial hymn, and their [mission] to guide lost souls. Use vivid imagery, such as 'a halo of dawn’s first light' or 'feathers woven from moonbeams.' Infuse the poem with a tone of [awe] or [serenity], depending on the angel’s purpose. Structure it as a [sonnet], [free verse], or [haiku sequence], and include a subtle metaphor comparing the angel to [a lighthouse in the storm] or [a whisper of eternity]. End with a line that lingers, like 'the echo of a prayer unanswered.'