I also learned this in Bost. oub solo. I read some where that they use the move more frequently when their hp is between 75%-100%, due to a coding error. They do also use the move at lower %s, just maybe not as frequently.

I geared up an evasion/haste set with genbu shield+ low dmg sword and just melee'd while keeping slow/blind (discharge/drape) on him, and almost every mob used it or killed me with doom first, lol.