"...Ruby, I'm not afraid of you!"
The body of the Desolation Plague Monster violently shuddered and contorted, struggling to break free from the oppressive fear, regaining its clarity. Only then did it realize its body was submerged in lava, and the Giant Rat shell it used as a cover had mostly been scorched to charcoal.
The Curse of Cursed Earth was a spell that did not differentiate between friend and foe. In those few seconds when it lost control, the rampant curse also harmed itself.
The plague-like inner tissues snapped open the Giant Rat's shell. The Desolation Plague Monster swam out, the lava parting to both sides, even the omnipresent storm quietly avoided it—as a master of controlling curses, once it regained clarity, it naturally couldn't be harmed by its own curses again.
...that demon indeed was formidable.
The Desolation Plague Monster thought.