Poorly cast & directed, but the script is a work of art.
HALLOWEEN 6 (and Halloween III) DECONSTRUCTED:
Consider the first six entries as one unit. Just the same way folks now look at the original + David Gordon Green's trilogy as a unit. (Or Rob Zombie's two films for that matter.)
They show "John Carpenter's Halloween" on television in Halloween III, as a sort of movie-within-a-movie. So, of course it doesn't literally connect, but where it does it connect is thematically with Season of the Witch acting as a sort of foreshadowing.
Screenwriter to Halloween 6, Daniel Farrands, while creating the Curse of Thorn storyline, carefully examined the previous entries and crafted a story that incorporates Dr. Loomis' druids/Samhaim rants, tribal sacrifices, Stonehedge, the ideas of cultish figures and ritualistic experimentation, the "unconscious mind", the Man in Black character from H5, the Dr. Wynn character from the original (who gave Myers driving "lessons"), and so forth, so that these six films still had a unity to them.
It's a series of two distinct pagan conspiracies, with the first obviously dominating the focus through many more films. The second, however, is much grander-in-scale since it's essentially nationwide mass murder of children.
The formula is consistent:
Dr. Loomis = Dr. Challis (protagonist)
Dr. Wynn = Conal Cochran (antagonist)
Smith's Grove staff = Suited androids
Cult of Thorn = Santa Mira residents
Science & Runes = Toys & Masks
Escaped relative of the female lead are also present in both:
Michael Myers = Harry Grimbridge
Laurie Strode = Ellie Grimbridge
In H6, it's obviously the adult Jamie Lloyd who's graduated to the escaped relative role.
What Farrands did was quite ingenious, but he has unfortunately never quite received the respect he deserved. At the time in 1995, he was seen by some of us as a true-blue Halloween aficionado. The original film can stand alone as merely a tale of an unstoppable mental-case killer who escapes and stalks babysitters. Farrands however took the subsequent entries and made—not a trilogy, but I suppose it would be a "hexalogy" focusing on old-school paganism and ritualistic sacrifice.
I still await a version of Halloween: The Curse of Michael Myers that combines the endings of the theatrical and producer's cuts. It could be done easily enough.
Producers Cut ending, edited slightly,
title crawl ---> "November 1st" ---> "Return to Smith's Grove"
Dr. Wynn: What are you doing wearing that? [referring to robes] Halloween is over.
Theatrical Cut ending, edited slightly. Michael is free-agent, slaughters doctors while continuing to search for Tommy Doyle & Kara Strode. Loomis presumed dead. Tommy saves the day and beats Michael to a bloody puss-filled pulp with a lead pipe. The End.