I changed the title to "School of the Holy Beast", since most results give that title, and I really couldn't find sources for "The Transgressor".

That "School of the Holy Beast" is a literal translation of the Japanese title has nothing to do with its validity as a title. "The Transgressor" is the official English title used on subtitled prints, officially-subtitled TV airings and also the Eiren database (the Motion Picture Producers Association of Japan) which lists official English titles provided by the films' production companies. I changed it back, and added "School of the Holy Beast" as a valid alternative title used on a US DVD release.

db.eiren.org has a very obvious search function and it's set to search titles by default. But anyway, here is the relevant entry. http://db.eiren.org/contents/03000000480.html

Officially-subtitled TV airings that are licensed directly from Toei use the same title. https://www.thehawaiiherald.com/2015/11/27/ngn-digital-channel-677-9/

As for actual subtitled 35mm prints: https://spank-the-monkey.typepad.com/blog/2006/11/repost_wild_jap.html "[...] made in 1974, and actually titled The Transgressor on this print [...]"

For Cult Epics, this being a boutique/niche video label that releases stuff like "Vintage Hardcore XXX Pornography" and "Nekromantik", it obviously makes sense to use a more outrageous and exploitative title like "School of the Holy Beast". (people sometimes also call it "Convent of the Holy Beast", FWIW - that's just literal translations for you...) I didn't say it was an invalid title: it is an alternative title for the American DVD release.

Where do you see "Holy Beast School", exactly? I'm a bit confused.

I really don't understand your appeal here. I know we know each other outside of this website but we're not talking as friends about our opinions of the title, surely? It's not as if I made this title up. I'm reporting the facts and as you can see I researched them too. My own opinion of either one of the titles doesn't come into play at all. I don't think I'm being subjective. Do I think 'The Transgressor' "should" be the title? Well, yes, but I think that because that seems to be the fact, not because that's how I like it.

What sort of impact does it have on other websites? I can only think of the positive impact since all those websites will now automatically have a correct, more widespread title, instead of the title of a lone stateside DVD release.

I like you as a person but I don't think our personal relationship has much to do with this question! As for "Kawaii akuma", I recorded it off TV last year when it aired...