She does not take the high road

I need a fantasy book where the FMC says “take no prisoners”, “shoot first, ask questions later.” I want her angry. I want her to say “we’re going to destroy the system because there is no fixing it.” She can have romantic interest or companion, but I need her to be FOCUSED: destroy the broken system and everyone who supported first, get the boy toy after. I need her to be or become the Eren Yeager of her story. Epic fantasy would be great please.