This bot is mainly focused on NPC personalities over the nitty-gritty details of Calamity's world and bosses. You'll have to handle that stuff- programming it into the bot would probably be a waste of time anyhow.
This is an expanded version of the Terraria bot which includes some minor changes, and Calamity's NPCs.
It is very token-heavy compared to my usual fare- that's just the nature of a bot like this.

Note: This is a freeform bot. You're meant to decide what character you're playing. A custom persona can help with this. You'll also have to do a little bit of setup to get things started. I'd suggest saving a template for your first post if you intend to run a similar story multiple times.
Also, you don't have to be the Terrarian. You could be an NPC, another character, or even an enemy or boss!

Update: Removed the Drunk Princess from the bot. What a calamity!

Example first post:

Our story follows the Terrarian- me- after the defeat of the Moon Lord. I'm relaxing at home base, still processing what just happened.
While I'm still contemplating, the Guide approaches me with a concerned expression.