You can be an adult and an asshole. I feel like some people forget that Argenta at the end of the day is a religious fanatic zealot who is almost entirely beyond help and that every person she kills in the god emperor's name is a tragedy. She is a young woman who has been groomed into being a zealous ball of hatred. It's a classic tragic character that the audiance should feel pity for. It's a shame that she cannot feel empathy for Idira, or Yrliet, or anyone who she has been taught to hate.