Deflorator is the one who penetrates her first. The hymen here doesn't really matter (maybe she broke it as a kid, riding a bike), though the experience does affect her even more if the hymen is broken as well during this occassion.
Modulator is the one whom she has all her early sexual experiences with, the partner who essentially teaches her - subconsciously and consciously - what sex is supposed to be like.
If a woman is lucky, both roles will be performed by a single partner, hopefully one she's in a loving relationship with.
While it may seem virgins are boring and inexperienced and overall a pain in the ass, in reality a good deflorator+modulator who knows what he's doing can mold a virgin over a period of a few months into exactly the kind of sexual partner he wants. There's no man a young woman trusts more sexually than her deflorator+modulator, and she'll go to great lengths to please him in bed, even trying & practicing things more experienced women would balk at. This ofc only applies as long as the deflorator+modulator acts like a normal dominant male in the relationship. If he's a weak beta he'll be a shitty modulator who won't teach her much, and she'll try all the things she'd never try with him - like deepthroat or take it in the ass - with whoever she dates next.
TLDR: a virgin is like a fresh 90. It sucks at start, but if you spec, gear, and glyph it properly, it'll be just as good as the ones them gladiators play.
finally a solid post on ot.