Should work with those from the sounds of it, as this mod only edits Events. Unless one of those edits provinces directly removing one of the ones this one scopes to it shouldnt have any problem. If I get time this weekend I'll look into it, but no promises.

Cipher's More Realm Laws, GirlPope, Religion Incestuous, Satanism+, Shieldmaiden and Sketchy Series. That's what I could think of

Shouldn't cause any issues, as its just a few events, nor should it really conflict with anything. Likely it wont work with major overhauls like HIP or WTWSMS but it shouldnt be causing any unresponsiveness.

What are you also running alongside it?

I tried this and it made the game unresponsive. Would this conflict with any particular mod? Thanks for the quick response

Should still work for the current version of CK2, no incompatibilities far as I know.

Is this still working?

It depends. There is a game rule that lets you pick historical (somewhere circa 1080) or random which is between 809-1200.

what year does it occur

FOR THE GREAT STALLION.

Update coming soon that includes new animals, new event chains, new titles, and new places that can be invaded!

New Zealand should be part of Austrialia.

Thought about making it be Norse, But I figured for balances sake I'd leave it as Catholic so it doesn't get Holy War'd to death, or some massive conspiracy to kill the horse before it even gets land. But, I'll keep toying with the idea and how to balance it if I do go that route.

I know you said it can't be a custom, but Norse is already in the game.

Could the horse be Norse, to fit with it being Odin's horse?