I've read so many 'Re:Zero' fanfics where Rem's devotion is portrayed as this unwavering, almost supernatural force. She's often written as someone who loves Subaru unconditionally, even when he's at his worst. The best fics don't shy away from showing how her loyalty borders on self-destructive, especially in AUs where Subaru doesn't reciprocate.
Subaru's conflicted feelings are usually the counterbalance—his guilt, his hesitation, his fear of leading her on. Some authors dive deep into his internal monologue, showing how he struggles between gratitude and the weight of her expectations. The tension between her pure devotion and his messy humanity is what makes these stories so compelling. The ones that stand out avoid making either character one-dimensional; Rem isn't just a simp, and Subaru isn't just a clueless guy.