heroine
the most important person or thing in a real-life situation:
What were the sporting events in the photographs, and who were the main characters involved?
I know plenty of families whose house is the main character in their lives.
informal
on social media(= websites and computer programs that allow people to communicate and share information on the internet), someone who feels confident, interesting, and important:
The concept of being the main character of your own life has become very popular on social media.
main character energyMost young people see having main character energy as a positive thing.

SMART Vocabulary: related words and phrases

Literature
accentual
action hero
alliterative
alternative history
anapest
femslash
fiction
fictionality
fictionally
fictive
non-canonical
non-character
non-literary
non-metrical
non-poetic
sympathetically
tanka
tartan noir
theatrics
threnody

You can also find related words, phrases, and synonyms in the topics:

Important people and describing important people
Internet terminology