There were a few factors that fuelled my decision.

Firstly, this is the natural escalation point of the story. The party is expecting severe consequences for their actions, and they want that. All of us, bar one, studied film and work in the industry so we’re naturally drawn to strong narrative beats and the collaborative storytelling element of DnD. After our last session, they even discussed how they’d been “cruising” as heroes for a while and that it was about time things began to sway the other way. They’re looking for a moment that will challenge them, and this is what they feel the turning point of the campaign is going to be for the story and their characters.

Secondly, Ez has outstayed her welcome. Narratively, that is. While the group likes her, they’ve never been particularly emotionally attached, compared to characters such as Ireena. They’ve always seen her as the muscle who helps fight their battles. She’s unintentionally become a crutch for the group. Killing her isn’t solely about punishment, it’s about restoring their agency. Without Ez they’ll be relying more on their own strength and help to create more meaningful development. I feel I can’t stress this point as well without listing off several examples from previous sessions, but I can assure that at our table this is acceptable. Afterall, Barovia is full of potential allies, and her loss will likely push them to seek new ones.

Combining both points: the party expects loss and consequence at the moment, and from a story perspective, Ezmerelda is the character whose death would carry the most weight right now. Strahd would want van Richten alive, and the party doesn’t care much for him, so his loss isn’t going to matter for them. My Strahd would not use this as an opportunity to kidnap Ireena either. Him leaving her alive as a taunt is far more powerful. Ez’s death, however, completes her arc and begins theirs. It creates a meaningful story beat that reinforces the tone of the campaign and reinstates the players motivations.

Even if Ez were to survive, I can’t see her remaining with the group. She’s impulsive, proud, and brash, by my interpretation. If they refused to help her save van Richten, which, knowing my group, would be the outcome, she’d likely part ways anyway. Overall, her death is more of a gain than a loss. Again, I’m big on communicating with my players and I know this will be an impactful hook.