You Shou Yan - Ch. 441 - Reinforcement/Second Rescue

[MangaDex]

 

[catalacyst]

Spoiler: MAJOR spoilers - Ch. 900+

I've only just now realized the thematical genius that, in this allegory for Tianlu's heart lock, Sibuxiang (deer) serves as both the warden of the prison, as well as the key to breaking out.