Most Carnages traits are worded: “When this creature kills another creature”
However, Canage Destructor is worded “When this creature attacks and kills a creature”
Due to the difference in wording, I assumed it was NOT possible to trigger the Carnage Destructor’s trait with a spell.
Then I cast Dark Ritual with my Carnage Destructor, and the trait triggered repeatedly (chain reaction) to wipe my entire team!
Please either change the wording of the trait (to make it more clear that you can trigger it with a spell cast), or else change the trait behavior.