Timeline
Rereading through the chapters, the events leading up to Asa breaking the barrier of Higashimura goes like this:
- Asa goes to hospital for ulcer treatment.
- She is kidnapped and murdered by the Higashi assassins.
- In her afterlife, she meets Break. She refuses to die and resurrects with the power of Break.
- Gabby finds her in the captive cell with the dead bodies of the assassins.
And, when she meant to break only Yuru's arrow, instead broke the entire wall, Asa apologizes because she is still getting the hang of it. Implying, the time between her "first" death and her breaking Higashi village's barrier was merely a day or two. Maybe, even hours, who knows? Asa is murdered, resurrected, lost an eye... yet instead of resting, she immediately rushes to rescue Yuru with a power she never asked for.
And, now you get why Gabby so mercilessly massacred all those villagers. It is one thing to see your friend so hounded by assassins she has to live in house arrest for her life; it's another to see your friend actually be coldbloodedly murdered by said assassins for absolutely no fault of hers. That too while Asa is visiting the hospital. A hospital. A hospital that is supposed to be a neutral zone even in wars.