This spell moves the target back in time one round, where they are either shielded from the time stream or not. If they are shielded they gain advantage on their next attack roll or spell attack roll. If they are not shielded, they have disadvantage on their next attack roll or spell attack roll
This spell moves you back in time one round, where you study what happened in the previous round. You reappear on your initiative the following round and have advantage on any attack roll or any spell that requires an attack role.