(It's been a while and it seems like no one else is going to answer)

Not an expert, but pointing out.

Constantine was the first Christian emperor, but conversion wasn't mandatory. It was Theodosius who truly made Romans "Christians"

The "Theodosian decrees" of 389-393 were the orders that removed all pagan altars from public buildings, disbanded the Vestal Virgins, outlawed the Olympic games, and punished witchcraft & auspices