Whenever one team has, let's say, the Shock effect. the character attacking should get damaged,  but instead, the character going next in the battle is damaged. For example F1 of the enemy team will attack me and my F2 will get hit with "DOT Self Damage" instead of the enemy F1. Works the other way too - if my B1 attacks with a self damage effect active, the enemy B2 actually takes that damage.