what pronouns are correct?

i always try to affirm other people’s gender and accept all people. however, this one person who harassed me, i blocked and can’t ask them directly. they used to be known as a girl named emma but they then said they were a guy with he/him pronouns named ethan. however, they then said that they were a troll and that they weren’t really a boy, even though they changed their snapchat avatar to a boy according to my fiancé who saw their profile and blocked them subsequently.

i’m using they for now but i will call them ethan whenever referring to them because that’s what their display name stated.

i’m still learning btw, don’t be rude pls 😓