Original sentence: His worst subject is Potions, and having the bullying Severus Snape as Potions Master made matters worse.However, he is highly gifted at Herbology.In Harry Potter and the Prisoner of Azkaban Neville begins to take a more confident role when Professor Remus Lupin chooses him as his assistant in a practical Defence Against the Dark Arts lesson in fighting a Boggart, a shape-shifter which takes the form a person most fears.Neville is petrified at fighting a Boggart which will take the form of his worst fear - Professor Snape - but his confidence grows when his attempt to repel the Boggart-Snape proves successful.Throughout the series, he is often portrayed as a bumbling, forgetful, disorganised character and a rather mediocre student
Edited sentence: Throughout the series, he is often portrayed as a bumbling, disorganised character and a rather mediocre student, though he is highly gifted at Herbology