Basically... The Calamity was the result of a weapon the Mancers were creating- a military faction within Caelondia that was valued for inventing things. Most notably, to many Ura, weapons. The Mancers wanted to use this weapon on the Tazal Terminals to completely exterminate what they viewed as the biggest threat to Caelondia.

Zia's father, Venn... had been forced into working for them, being the only one who actually knew how to create this weapon and how to make it work. After meeting Zia, I learned about this and together we decided to try and enlist the help of a different Mancer to see if we could sabotage the weapon and make it unable to work at all. That was Rucks.

[Throughout this short tale, Zulf manages to keep his voice more or less level although there's no hiding the quiet rage bubbling underneath.]

It didn't work, as is plain to see.