Should a dramatic series be downloaded if a female relative promises to do so, with the fear that it might be counted among sins?

You are not obligated to fulfill this promise to your relative; rather, it is impermissible, as it constitutes cooperation in sin and transgression, which is forbidden, based on the Almighty’s saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." Watching TV series is forbidden due to the sins and evils they contain, which corrupt religion and morals. Therefore, apologize to her and inform her of the impermissibility of watching them, for if you fulfill your promise to her, you will be her partner in sin.