Rasguñan comes from the verb rasguñar, meaning "to scratch" or "to claw". It's a vivid and somewhat aggressive verb that isn't commonly found in romantic song lyrics.
In "Maldito Sea El Amor", iLe uses it to describe how even embraces can "scratch" or harm love: "Malditos sean los abrazos / Que rasguñan el querer" (Cursed be the embraces / That scratch at love). This unexpected imagery makes the word stand out and adds a layer of complexity to the song's theme of cursed love.
iLe opens on a curse: "Malditos sean los amores" [Damn be the loves] "Que te amarran sin consuelo" [that tie you down with no comfort] — love here isn't warmth, it's rope. She keeps pushing the image further, calling it a labyrinth with no way out and chains nobody knows how to loosen, and asks for something to cut through it: "Una luz algún instinto que desate en mi la paz" [A light, some instinct, to set peace loose in me].
But the song never lets her find that light. She describes herself "Como muerta en vida" [like dead while alive], going quiet the moment things get difficult — "Cuando se oculta enseguida, quieta" [when it hides itself right away, still] — "Sin siquiera reaccionar" [without even reacting]. It's less a breakup song than a portrait of staying frozen inside a relationship that has already turned into a cage, cursing the very feeling that put her there.