Dev Patel is just as wrong for Sir Gawain as he as for David Copperfield, but it's not his fault that The Green Knight is an incoherent mess; the responsibility lies entirely with writer/director/editor David Lowery. Early on in the film, King Arthur (Sean Harris) tells Gawain, "Tell me a story about yourself so I can get to know you." Gawain replies that he has no story to tell; two hours later he still doesn't have one save for a few disjointed episodes that ultimately equal less than the sum of their parts.
Poor time management is another issue; it takes the movie a very long 15 minutes to introduce the Green Knight (voice of Ralph Ineson), but when he issues his challenge, Gawain immediately jumps the gun without giving anyone else even a chance to turn it down.
This situation, which offers great dramatic possibilities, is the one that Lowery should milk for all that it’s worth; on the other hand, maybe he’s aware of how disappointing his Green Knight is and wants to get him out of the way as soon as possible until he inevitably has to reappear at the end.
Sean Connery’s Green Knight from Sword of the Valiant looks like the bastard son of Santa Claus and Saint Patrick, but at least he’s flesh and blood and played by an exceptional actor; that is to say, a million times better than the medieval Groot that Lowery comes up with.
This Green Knight is not just ugly, but also dumb. He carries a letter explaining the reason for his visit; this missive is read by the Queen in a distorted voice, as if she was possessed or something; is the Knight, whose severed head is capable of speech, speaking through her? And if so, what exactly is the point of the letter then?
Of course, after the frustrating resolution that resolves nothing (complete with an example of It's A Wonderful Plot, specifically the kind experienced by Willem Dafoe in The Last Temptation of Christ) a better question would be, what's the point of this movie?
This film is the product of a shamelessly shifty director; Lowery not only casts a 'diverse' actor in the lead, but also resorts to queerbaiting in the form of a kiss between Patel and Joel Edgerton (something similar occurs in the original century XIVpoem, so we’re hardly breaking new ground here). The latter of which is doubly reprehensible, because the way the kiss is misrepresented only succeeds in making Gawain seem homophobic.