The phrase "although the protagonist" is correct and usable in written English.
It can be used to introduce a contrast or exception regarding the protagonist in a narrative or discussion.
Example: "Although the protagonist faced numerous challenges, they remained determined to achieve their goals."
Alternatives: "even though the main character" or "despite the fact that the protagonist".
Indeed, although the protagonist of "The Woman in the Window," a thirty-nine-year-old child psychologist named Anna Fox, is wryly self-aware, her mode of narration resembles a film script.
Perversely, although the protagonist is the wronged Vern (Arthur Kennedy), whose fiancee has been raped and killed by bandits unknown, Lang's film - which, as we are constantly reminded by its theme song, tells a tale of "hate, murder and revenge" - is more concerned with the owner of an outlaw casino bar called Chuck-A-Luck, somewhere near the Mexican border.
Eric enters Tampa AM, having only filled out his own registration form although the protagonist trusted him to sign them both up.
While driving together the pair flirt, although the protagonist finds it difficult to overcome his reluctance: "I would go out tonight, but I haven't got a stitch to wear".
A passing "charming man" in a luxury car stops to offer the cyclist a lift, and although the protagonist is at first hesitant, after much deliberation he accepts the offer.
Although the protagonist Chiang's "view of human beings other than himself is patronising at best" and might leave readers with a "rather sour aftertaste", the novel's "light touches of romance and compassion do much to lift the storyline" and had "masterful pacing".
Although the protagonists were naturally keen not to identify themselves, they captured the island's imagination.
Although the protagonists of these movies typically acted out their goals in violence, this did not become the Wu-Tang model.
Although the protagonists adhered to many stereotypes common to romance novels of the 1980s, Roberts's heroine is more independent and feisty than most heroines of the time.
Although Kain is the protagonist of the previous game, Blood Omen: Legacy of Kain, he is the primary antagonist and final boss of Soul Reaver.
Although the fate of the protagonist – an old Bolshevik imprisoned during the Stalinist purges – is never really in doubt, the deceptively simple language and brilliant use of memory, the intensely focused imagery and the inventive use of perspective, carry the reader to a conclusion that is both startling in its psychological intimacy and deeply moving.
