Ocaso literally means "sunset" or "decline." It's a more poetic and less common word than simply saying "noche" (night) or "final" (end).
In the song, it's used metaphorically in the line "Se quedó conmigo en el ocaso," referring to a period of decline, difficulty, or the end of hope. It beautifully conveys the idea of someone staying by your side even when things are at their worst or fading away.
Have you ever felt like someone stuck by you through thick and thin, no matter what? That's exactly what Jesús Adrián Romero sings about in "Se Quedó Conmigo" [He Stayed With Me]. This song is a beautiful tribute to unwavering loyalty and support.
Romero sings about how this person "Se quedó conmigo en el fracaso" [He stayed with me in failure] and "en mi oscuridad y mis momentos bajos" [in my darkness and my low moments]. Even when he lost his way, "cuando perdí mi norte" [when I lost my north], this person was there, patient and understanding. It's a powerful message about someone who promises to be with you "hasta el final" [until the end] and never give up on you, even "cuando en mi fe se meta el sol" [when the sun sets on my faith] or when you stumble. It's a truly comforting song about having someone who will always guide you with love.