It's more just because I hate making boss fights at all, it's an absolute ton of work. The Hovering Inferno in Incendium is partially based on the same thing, but that took me a week to make and even that isn't something I'm quite proud of.
Thank you for featuring Terralith! I'm glad I was able to make some PMC users happy with my work. It has been a tremendous amount of effort but I'm grateful it's gotten such a positive response.