The hardening of Carol into the sleepless sniper we see on season 10 was a long process of swapping hopefulness and tragedy. Every time Carol begins to settle into a domestic rhythm, the harsh, post-apocalyptic world of The Walking Dead punishes her for her complacency. After Sophia, Lizzie and Mika provide Carol with a sense of purpose. Their deaths force her to abandon that notion that she's exclusively valuable to the survivors as a caregiver and mother figure. She latches onto Daryl Dixon (Norman Reedus) and begins to reinvent herself as a ruthless zombie slayer. This new Carol suits the moment, but it doesn't last.
After Alexandria neutralizes the threat of Negan's survivors, Carol finds her new lethal skill set less in demand. During an extended period of peace, she settles down with King Ezekiel and their new adopted son, Henry. The domestic Carol resurfaces, and it looks like she might get a happily-ever-after with her new family — until the Whisperers arrive on the scene. After Alpha (Samantha Morton) and her skin-wearing horde mark the border around their land with Henry's severed head, Carol races back into war mode. She abandons Ezekiel and leaves the Kingdom, burning every vestige of her peaceful life to the ground.
It's been a fascinating transformation to watch, if not a particularly uplifting one. Remember, as early as season 3, Carol ruthlessly murdered a pair of sick survivors that she feared might infect the rest of the group — a crime for which she was temporarily banished from the crew. That was a major character shift at the time, but one that makes sense in hindsight.
