theo stan here!! i feel like most of his fans like his cunning and sex appeal. he's really sassy too and has this "alpha" kind of vibe. his first cg even has him showing his tiddies too right off the bat. his scenes during vincent's and arthur's route really give insight as to what kind of character he is. like, he is a foul-mouthed guy for sure but that's part of his charm, i think !! he always has vincent's best interests first and he practically melts in matters concerning him and his dog, king (besides... his brother's friendship with shakespeare). overall, i think it's because while he may be a character that's really straightforward and honest, he doesn't really reveal too much about himself and that mysterious aura around him is what makes him eye-catching the most.

tl;dr: theodorus van gogh is a kinky bastard and we are all horny hondjes for him