Just looking for any recommendations about MCs (Male or Female) who used to live in ancient times and then, through whatever means, appeared in modern day. I suppose going to ancient times and then returning also fits the bill. No BL, no Harem. Thanks. (Ignore the reason for this, totally didn’t get a craving after someone else was asking for a forgotten title *cough cough*)
it doesn't exactly fit your criteria but Cultivation Chat Group has a "main" side character(a.k.a Senior White) like that.
Female MC: Rebirth to the Eighties to Get Rich (new) Retired Villainess Transmigrates into a Cannon Fodder (cultivation MC, into quick wear) Transmigration of the Famous Cyber Star (personal favorite)