Bringing some more examples in, The Festival is a great example of how she behaves around those that she is comfortable around. Her friendly behavior towards Snap is like a contradiction to the way that she treats those she sees as lacking. When the cowardly bully shows up and nags on Snap, she didn't laugh at his expense but rather defended him as a loyal friend would. While not the type to go into feelings, she still attempted at cheering him on through spending time together until he was ready to talk.

TL;DR

Amaryllis is a small, axe-crazy noble who makes herself incredibly difficult to approach through her brash and sadistic personality. Those that get past it and manage to impress her will find that she is actually a very loyal individual to her close friends and capable of caring. Her flaws and strengths have her feel like a rather nuanced character who you see develop into someone who steadily contributes more to the team and story with her reserved history and knowledge.

As per her own oath, she is there to leave a legacy and only expects success. She has the strength to stand up for herself and those around her. A true team leader in qualities, and someone that would make for a good protagonist in her own story.

Certainly. I'd love to. Would do me good to organize my thoughts.

Amaryllis is introduced in episode 2 immediately as what can be seen as the typical school bully archetype. Her and her apparent sidekick, Snapdragon, who both poke and prod one of the main protagonists each. Amaryllis picking on Sage for only sticking to old magic and Snap picking on Rosemary… because holy moly he's less secure than a crumbling barn I once had.

Snap aside, back to Amaryllis. First impressions has her immediately in conflict with the show's main characters… except it's quickly shown to be due to a sort of superiority complex where she only picks on those that she thinks deserves such. When she was partnered with Sage and Thyme, you can see her readily notice and respect Thyme's logical thinking and blunt honesty. They even become partners again the episode right after that and get good screen time and development in getting to know the other.

The cruel and sadistic side of her humour is tied with her misanthropic outlook, but that is rather relatable after having to deal with others that fall short of perceived logic. Should you manage to impress such an individual and get past their rough, exterior personality, you'll actually find them to be quite endearing and thoughtful. It's like a privacy screen they set up for themselves, and you can start to see more and more of Amaryllis in the later parts of the show as she opens up to the main cast.