Since Sylvia has lines about wanting to "boss around" male elves, you could have her be dominant in the love route and submissive in the slave route. I think Sylvia is the hottest character in the game.
Which says a lot cause all the characters are hot, it's a great game! I started playing it 5 days ago and it's waay better than other games of the same kind. I'd support you on patreon, but I'm unfortunately broke •~•