Whenever we introduce a new NPC alongside a league, I am filled with a confusing blend of excitement and dread. Sister Cassia, the NPC introduced alongside Blight, was no exception.

NPCs like Cassia have to do a lot of heavy lifting. They are often your first point of contact with the league, and are thus responsible for helping teach the league's mechanics and intricacies. But on top of that, they also have to provide a lot of context for the mechanic. It's one thing to add tower defence into Path of Exile. It's another to make it fit within the world, and to give the player a purpose to interact with it beyond the juicy rewards.

A personal goal of mine, however, is to ensure that even if you don't enjoy the specific mechanics of a league, you'll still enjoy the presence of the NPC. That means each new NPC needs to feel distinct from those already present -- not just the masters in your hideout, but the dozens of other characters you interact with throughout the campaign.

Cassia was an interesting character to work on. Quite early on we decided she'd be a nun, as Elreon's betrayal meant we didn't have much of a Templar presence anymore, and given the society all the Exiles hail from, having a technical background meant likely having a close relationship with the Templar (the group, not the player class). Internally, she was referred to as "Technonun" for a while as her final name was nailed down. Fun Fact: Cassia is another name for Cinnamon, a plant with natural fungicidal properties!

Knowing she was a Templar with technical prowess, it wasn't a huge leap in logic to assume she probably knew Dominus and Piety. It's hard to make someone with those close associations 'good', which is fine, because few people in Wraeclast are truly good. I loved the idea of her being morally ambiguous, but broadly doing something healthy for Wraeclast (killing the blight). Her previously high-status among the Templar allowed her to be believably snobby and condescending, as a counterpoint to the broadly-helpful pool of Masters we currently have.

Often I'll sketch out a character's backstory (Templar engineer, exiled for misappropriating Templar resources, still somewhat brainwashed) and as I'm working on the script, the more important personality traits will emerge. Her habit of over-explaining, her hymn-singing and her strong disdain for Piety all developed across the first draft or two of her script.

Once we were happy with the script, we cast the wonderfully talented Jodie Rimmer to play her. I'd written out three goofy lines to be sung as hymns, and wanted her to also hum the league's theme. During recording, I suggested one tune be sung as if it were for a marching army (hence the upbeat tune about burning the unrighteous). I love that, on its surface, those songs are amusing and tell you a lot about Cassia, and on further reflection, tell you even more about the Templar themselves, and the story of Sin and Innocence.

Originally I'd planned for her to sing a lyric once and then go quiet -- essentially Cassia's equivalent of "Still sane, Exile?" -- but once it was implemented, it felt too weird for her singing to suddenly stop. We put the longer-form lines in and trimmed the "oh!" off of her greetings on a whim, and it just totally worked.

I was very pleased with how well she was received, though like many of you, I wish we'd recorded more lines for her. There's always a balance to be struck between good signalling, where you know she's telling you there's a new minion lane or that monsters are too close, and enough variety that you don't get sick of hearing those signals. In this case, I think we probably erred too much on the signalling side and not enough on the variety. Hopefully we'll get a chance in the future to expand her character a little more! I'd love for her to tell us what she thinks of all the masters.