the deal with thee/thou vs. you was that thee/thou was more personal/intimate, while 'you' was more formal

then english got over having grammatical relationship distance in pronouns & used 'you' everywhere

so when someone in an old-timey story says "Have at thee, villain!", they're actually flirting

(also "villain" literally means "landowner" — someone who has a villa.)

"Have at thee, villain!" --> "Hi I like your hair, and since you have a house and stuff I was wondering if I could move in with you?"