Setup: Have two valkyrie scouts on one side of a fight (in my case, it was enemies, but player party should suffice too). Make sure both of them become confused. Have one damage their own team via confusion.
Result: Both valkyrie scouts’ Fight or Flight traits will trigger on the confused monster, doing the usual 30% damage. However, this damage also counts towards activating Fight or Flight. The valkyries shall now start repeatedly counterattack themselves until one of them dies.
Bigger concerns: Other than the fact that two full health monsters doing 30% damage to each other will take a LONG time to chew through, even with turbo mode, should one or both creatures have the misfortune of having artifacts that can heal them faster than they can damage each other, the game could potentially become stuck in an infinite loop of counter-attacks that may necessitate closing the game with the three-finger salute.