Although it works fairly well, there will be times when you’ll toggle between spell sets without knowing it because once you defeat an enemy you’re left with two choices: save it (left bumper) or sacrifice it (right bumper). With the right bumper pulling double duty you can accidentally switch while sacrificing a fallen adversary, and as a result you may, for example, heal yourself instead of firing a projectile. This is mostly an inconvenience except in the cases when your offering is nearly exhausted — then you can actually break a spell and lose use of it for the duration of the fight.