They *were* being abusive.
When planning something big, helps to stop a second and think "has anything on this scale ever been pulled off in BM before?" and, if the answer is "no", think carefully about "why", and if it should stay that way.
So think about that for a moment, "have adventurers ever been able to destroy a realm within a single turn" before? Do you really think adventurers being able to blow a realm off the face of the earth is intended behavior?
