Setup: Nix Scoundrel (enemies start with scorned) with Xyrxzy’s Control on its artifact. “After this creature Attacks, the enemy Attacks itself as well. The amount of damage is based on this creature’s Attack.” No instability. Enemies not resistant to debuffs.
Nix Scoundrel attacks enemy (which is scorned) and enemy attacks itself.
Since enemy is scorned, I would assume it should not be able to attack itself. Maybe the trait just needs to be re-worded as “enemy deals damage to itself”?