Five items capture the extent to which a viewer emotionally merges with advertising drama characters, feeling as though the depicted events are happening to them personally. Empirically distinguished from sympathy, which involves understanding but not sharing a character's feelings.
Escalas, J. E., & Stern, B. B. (2003). Sympathy and empathy: Emotional responses to advertising dramas. Journal of Consumer Research, 29(March), 566–578.
Free access to 2023+ psychometric scales at PsychScales