I can't believe the news today

I can't close my eyes and make it go away

we survive, it's more than pride

The Blast Worms are Yason warriors far stronger than your average Yason. They have developed a genetic defense against rheuma, allowing their vindi to draw chi from all of nature, not just the Tree of Light. They also have the ability to summon familiars. Familiars are basically beast which answer only to them and their commands, and supposedly, when the master dies, the familiar dies as well.

Though we don't see it, Carian suggest their is division between normal Yason and Blast Worms, and that should Rheuma be cured and there no longer be a need for Blast Worms protection, they would be looked down upon. It's probably important to remember that the Yason lived peacefully with nature and the tree, and that they'd probably see the Blast Worms as an oddity.