Yx vs BY

While the story revolves love around YX… but idk why she so naive…even told and see how men can hurt her but still want to save TH…She’S indeed strong but she easy to believe in men words make her weak..Meanwhile BY was a powerful physician.. but cant heal himself..but since its LHY i still love his character..It supposed after YX Resurrected again BY are the one who keep helping her but she choose ti save TH.. why can she just stay beside BY