Muggles' Guide to Harry Potter/Characters/Montague

Overview
Montague is a Slytherin, probably one or two years older than Harry Potter.

Prisoner of Azkaban
Montague is mentioned as being on the Slytherin Quidditch team, where he plays in the final against Gryffindor. He and team Captain Marcus Flint, between them, rack up a very impressive number of fouls. During the match, he scores Slytherin's second and last goal.

Order of the Phoenix
It is mentioned that Montague is the new captain of the Slytherin Quidditch team, presumably replacing Marcus Flint. The commentary on the game lets us know that he is playing as one of the three Chasers again.

Dolores Umbridge appoints Montague to be on her Inquisitorial Squad. He attempts to dock House points from Fred and George Weasley, and they shove him into an old, broken Vanishing Cabinet. Some short time later, he reappears, apparently partly embedded in one of the toilets. He never seems to fully recover from this misadventure, and while his parents do visit at one point, he is still in the Hospital Wing at the school as OWL exams finish up in mid-June — when Harry goes to the Hospital Wing to speak with Professor McGonagall after his vision in the History of Magic exam, Madam Pomfrey is spooning blue potion into Montague's mouth.

Half-Blood Prince
Draco Malfoy reveals that when he was trapped in the Vanishing Cabinets, Montague had found himself sometimes hearing things happening inside the school, sometimes hearing things happening inside Borgin and Burkes. Realizing that the two cabinets were linked, Draco had repaired the Cabinet at Hogwarts, and had used that to allow Death Eaters to enter Hogwarts.

Strengths
It is mentioned that Montague is physically quite strong, and evidently he is a competent flyer.

Weaknesses
It is strongly suggested by the author that after his shattering sojourn in the Vanishing Cabinets, and the bad landing from his Apparating out of that situation, that his mental abilities are impaired, as is his physical strength.

Analysis
We are never actually told about Montague's strength, either mental or physical, after the events in the Vanishing Cabinet. We are, however, given some very strong hints.

On the mental acuity side, when we see him mid-June, Madam Pomfrey is spooning some blue potion into his mouth. The implication inherent in the word "spooning" is that Montague is not capable of steering the spoon himself. On the physical side, it is certain that Montague remained in the Hospital Wing from when the accident occurred, about April, to at least mid-June. Even for wizards as young and healthy as Montague, that much confinement must cause some muscle mass loss. One certainly gets a picture of a near-invalid, confined to the Hospital Wing for two months, and still unable to feed himself.